WO2022169222A1 - Technique for transmitting long training signal in wireless lan system - Google Patents

Abstract

The present specification proposes a technical feature relating to a long training field (LTF) of a wireless LAN system. One LTF signal based on the present specification may include a plurality of consecutive LTF symbols, wherein the plurality of LTF symbols may include an initial LTF symbol and an extra LTF symbol. The initial LTF symbol and the extra LTF symbol may be generated through multiplication of a preconfigured LTF sequence and an orthogonal matrix. The orthogonal matrix of the present specification may be variously configured according to the number of LTF symbols. For example, the number of rows or columns of the orthogonal matrix of the present specification may be configured on the basis of the total number of LTF symbols included in one LTF signal, or the number of initial LTF symbols or extra LTF symbols.

Description

A technique for transmitting a long training signal in a wireless LAN system

This specification relates to transmitting a training signal in a wireless communication system, and more particularly, to transmitting a long training signal in a wireless LAN system.

A wireless local area network (WLAN) has been improved in various ways. For example, the IEEE 802.11ax standard proposes an improved communication environment using OFDMA (orthogonal frequency division multiple access) and DL MU downlink multi-user multiple input, multiple output (MIMO) techniques.

This specification proposes technical features that can be used in a new communication standard. For example, the new communication standard may be an Extreme high throughput (EHT) specification that is being discussed recently. The EHT standard may use a newly proposed increased bandwidth, an improved PHY layer protocol data unit (PPDU) structure, an improved sequence, a hybrid automatic repeat request (HARQ) technique, and the like. The EHT standard may be referred to as an IEEE 802.11be standard.

In the EHT standard, a wide bandwidth (eg, 160/320 MHz), 16 streams, and/or multi-link (or multi-band) operation may be used to support high throughput and high data rate.

In the EHT standard, a wide bandwidth (eg, 160/240/320 MHz) may be used for high throughput. In addition, in order to efficiently use bandwidth, preamble puncturing and multiple RU transmission may be used.

A Physical Protocol Data Unit (PPDU) of a Wireless Local Area Network (WLAN) system includes a Long Training Field (LTF) signal. The LTF signal consists of at least one LTF field. The number of LTF fields included in one LTF signal may be determined based on the number of spatial streams related to the PPDU. For example, when the number of spatial streams is three or four, the number of LTF fields is fixed to four. For example, when the number of spatial streams is 5 or 6, the number of LTF fields is fixed to 6. For example, when the number of spatial streams is 7 or 8, the number of LTF fields is fixed to 8.

A new WLAN system including the EHT standard can support an increased number of spatial streams. When the number of spatial streams is supported, a technical effect of increasing peak throughput may occur. If the number of spatial streams increases, the number of related LTF symbols may also increase. Also, for the purpose of improving the performance of channel estimation, the number of conventional LTF symbols may be increased. That is, the number of LTF symbols may be increased for various purposes and effects, and various technical characteristics regarding the increased LTF symbols should be defined.

This specification proposes various technical features. Various technical features of the present specification may be applied to various types of apparatuses and methods.

For example, the method based on the present specification may include, in a transmitting station (STA), configuring a Long Training Field (LTF) signal for channel estimation. For example, the number of LTF symbols included in the LTF signal may be the sum of the number of initial LTF symbols and the number of extra LTF symbols. The number of initial LTF symbols may be determined based on the number of spatial streams configured by the transmitting STA.

The initial LTF symbol may be configured based on a multiplication of at least a portion of an LTF sequence and a P matrix. The P matrix may be determined based on the number of spatial streams. The number of extra LTF symbols may be determined based on the number of initial LTF symbols. The extra LTF symbol may be configured based on a multiplication of at least a portion of the LTF sequence and the P matrix.

The number of LTF symbols may be increased for various purposes. When the number of LTF symbols increases, a technical effect of improving the reception performance of the receiving STA occurs because the performance of channel estimation is improved.

An example of the present specification proposes a technical feature for efficiently generating an increased LTF symbol. For example, the present specification proposes a technical feature of generating an initial LTF symbol and an extra LTF symbol based on at least one orthogonal matrix (or P matrix). In addition, an example of the present specification proposes an improved technical feature indicating information related to an increased LTF symbol. Based on an example of the present specification, information related to the increased LTF symbol may be accurately transmitted to the receiving STA, and the receiving STA may increase channel reception performance through this.

1 shows an example of a transmitting apparatus and/or a receiving apparatus of the present specification.

2 is a conceptual diagram illustrating the structure of a wireless local area network (WLAN).

3 is a diagram illustrating an example of a PPDU used in the IEEE standard.

4 is a diagram illustrating an arrangement of a resource unit (RU) used on a 20 MHz band.

5 is a diagram illustrating an arrangement of a resource unit (RU) used on a 40 MHz band.

6 is a diagram illustrating an arrangement of resource units (RUs) used on an 80 MHz band.

7 shows the structure of the HE-SIG-B field.

8 shows an example in which a plurality of user STAs are allocated to the same RU through the MU-MIMO technique.

9 shows an operation according to UL-MU.

10 shows an example of a channel used/supported/defined in the 2.4 GHz band.

11 shows an example of a channel used/supported/defined within the 5 GHz band.

12 shows an example of a channel used/supported/defined within the 6 GHz band.

13 shows an example of a PPDU used in this specification.

14 shows a modified example of a transmitting apparatus and/or a receiving apparatus of the present specification.

15 is a diagram illustrating an arrangement of resource units (RUs) used on an 80 MHz band.

16 shows an example of an EHT PPDU.

17 shows an example of a first control signal field or a U-SIG field of the present specification.

18 illustrates a general technique for generating an LTF signal.

19 is a diagram illustrating a concept of constructing an LTF symbol based on a conventional HT-LTF generation sequence.

20 is a block diagram illustrating the format of an EHT Capabilities element.

21 is a diagram illustrating an example in which a P matrix corresponding to TN_LTF is used.

22 is a diagram illustrating an example in which a P matrix corresponding to the total number of spatial streams or IN_LTF is used.

23 is a flowchart illustrating an operation performed by a transmitting STA.

24 is a flowchart illustrating an operation performed by a receiving STA.

In this specification, “A or B (A or B)” may mean “only A”, “only B” or “both A and B”. In other words, in the present specification, “A or B (A or B)” may be interpreted as “A and/or B (A and/or B)”. For example, “A, B or C(A, B or C)” herein means “only A”, “only B”, “only C”, or “any and any combination of A, B and C ( any combination of A, B and C)”.

A slash (/) or a comma (comma) used herein may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.

As used herein, “at least one of A and B” may mean “only A”, “only B” or “both A and B”. In addition, in this specification, the expression “at least one of A or B” or “at least one of A and/or B” means “at least one It can be interpreted the same as “at least one of A and B”.

Also, as used herein, “at least one of A, B and C” means “only A”, “only B”, “only C”, or “A, B and C” any combination of A, B and C”. Also, “at least one of A, B or C” or “at least one of A, B and/or C” means may mean “at least one of A, B and C”.

In addition, parentheses used herein may mean “for example”. Specifically, when displayed as “control information (EHT-Signal)”, “EHT-Signal” may be proposed as an example of “control information”. In other words, “control information” of the present specification is not limited to “EHT-Signal”, and “EHT-Signal” may be proposed as an example of “control information”. Also, even when displayed as “control information (ie, EHT-signal)”, “EHT-signal” may be proposed as an example of “control information”.

Technical features that are individually described in one drawing in this specification may be implemented individually or may be implemented at the same time.

The following examples of the present specification may be applied to various wireless communication systems. For example, the following example of the present specification may be applied to a wireless local area network (WLAN) system. For example, the present specification may be applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11ax standard. In addition, the present specification may be applied to a newly proposed EHT standard or IEEE 802.11be standard. In addition, an example of the present specification may be applied to a new wireless LAN standard that is an enhancement of the EHT standard or IEEE 802.11be. Also, an example of the present specification may be applied to a mobile communication system. For example, it may be applied to a mobile communication system based on Long Term Evolution (LTE) and its evolution based on the 3rd Generation Partnership Project (3GPP) standard. In addition, an example of the present specification may be applied to a communication system of the 5G NR standard based on the 3GPP standard.

Hereinafter, technical features to which the present specification can be applied in order to describe the technical features of the present specification will be described.

1 shows an example of a transmitting apparatus and/or a receiving apparatus of the present specification.

The example of FIG. 1 may perform various technical features described below. 1 relates to at least one STA (station). For example, the STAs 110 and 120 of the present specification are a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), It may also be called by various names such as a mobile station (MS), a mobile subscriber unit, or simply a user. The STAs 110 and 120 of the present specification may be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, and a relay. In the present specification, the STAs 110 and 120 may be referred to by various names such as a receiving device (apparatus), a transmitting device, a receiving STA, a transmitting STA, a receiving device, and a transmitting device.

For example, the STAs 110 and 120 may perform an access point (AP) role or a non-AP role. That is, the STAs 110 and 120 of the present specification may perform AP and/or non-AP functions. In this specification, the AP may also be indicated as an AP STA.

The STAs 110 and 120 of the present specification may support various communication standards other than the IEEE 802.11 standard. For example, a communication standard (eg, LTE, LTE-A, 5G NR standard) according to the 3GPP standard may be supported. In addition, the STA of the present specification may be implemented in various devices such as a mobile phone, a vehicle, and a personal computer. In addition, the STA of the present specification may support communication for various communication services such as voice call, video call, data communication, and autonomous driving (self-driving, autonomous-driving).

In the present specification, the STAs 110 and 120 may include a medium access control (MAC) conforming to the IEEE 802.11 standard and a physical layer interface for a wireless medium.

The STAs 110 and 120 will be described based on the sub-drawing (a) of FIG. 1 as follows.

The first STA 110 may include a processor 111 , a memory 112 , and a transceiver 113 . The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two or more blocks/functions may be implemented through one chip.

The transceiver 113 of the first STA performs a signal transmission/reception operation. Specifically, IEEE 802.11 packets (eg, IEEE 802.11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the first STA 110 may perform an intended operation of the AP. For example, the processor 111 of the AP may receive a signal through the transceiver 113 , process the received signal, generate a transmission signal, and perform control for signal transmission. The memory 112 of the AP may store a signal (ie, a received signal) received through the transceiver 113 and may store a signal to be transmitted through the transceiver (ie, a transmission signal).

For example, the second STA 120 may perform an intended operation of a non-AP STA. For example, the transceiver 123 of the non-AP performs a signal transmission/reception operation. Specifically, IEEE 802.11 packets (eg, IEEE 802.11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the processor 121 of the non-AP STA may receive a signal through the transceiver 123 , process the received signal, generate a transmission signal, and perform control for signal transmission. The memory 122 of the non-AP STA may store a signal (ie, a received signal) received through the transceiver 123 and may store a signal (ie, a transmission signal) to be transmitted through the transceiver.

For example, an operation of a device denoted as an AP in the following specification may be performed by the first STA 110 or the second STA 120 . For example, when the first STA 110 is an AP, the operation of the device marked as AP is controlled by the processor 111 of the first STA 110 , and is controlled by the processor 111 of the first STA 110 . Related signals may be transmitted or received via the controlled transceiver 113 . In addition, control information related to an operation of the AP or a transmission/reception signal of the AP may be stored in the memory 112 of the first STA 110 . In addition, when the second STA 110 is an AP, the operation of the device indicated by the AP is controlled by the processor 121 of the second STA 120 and controlled by the processor 121 of the second STA 120 . A related signal may be transmitted or received via the transceiver 123 that is used. In addition, control information related to an operation of the AP or a transmission/reception signal of the AP may be stored in the memory 122 of the second STA 110 .

For example, an operation of a device indicated as a non-AP (or User-STA) in the following specification may be performed by the first STA 110 or the second STA 120 . For example, when the second STA 120 is a non-AP, the operation of the device marked as non-AP is controlled by the processor 121 of the second STA 120, and the processor ( A related signal may be transmitted or received via the transceiver 123 controlled by 121 . In addition, control information related to the operation of the non-AP or the AP transmit/receive signal may be stored in the memory 122 of the second STA 120 . For example, when the first STA 110 is a non-AP, the operation of the device marked as non-AP is controlled by the processor 111 of the first STA 110 , and the processor ( Relevant signals may be transmitted or received via transceiver 113 controlled by 111 . In addition, control information related to the operation of the non-AP or the AP transmit/receive signal may be stored in the memory 112 of the first STA 110 .

In the following specification (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device , (transmission/reception) apparatus, network, and the like may refer to the STAs 110 and 120 of FIG. 1 . For example, without specific reference numerals (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting) A device indicated by a /receiver) device, a (transmit/receive) apparatus, and a network may also refer to the STAs 110 and 120 of FIG. 1 . For example, in the following example, an operation in which various STAs transmit and receive signals (eg, PPPDUs) may be performed by the transceivers 113 and 123 of FIG. 1 . In addition, in the following example, an operation in which various STAs generate a transmit/receive signal or perform data processing or calculation in advance for the transmit/receive signal may be performed by the processors 111 and 121 of FIG. 1 . For example, an example of an operation of generating a transmission/reception signal or performing data processing or operation in advance for a transmission/reception signal is 1) Determining bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU /Acquisition/configuration/computation/decoding/encoding operation, 2) time resource or frequency resource (eg, subcarrier resource) used for the subfield (SIG, STF, LTF, Data) field included in the PPDU, etc. operation of determining / configuring / obtaining, 3) a specific sequence (eg, pilot sequence, STF / LTF sequence, SIG) used for the subfield (SIG, STF, LTF, Data) field included in the PPDU operation of determining / configuring / obtaining an extra sequence), etc., 4) a power control operation and / or a power saving operation applied to the STA, 5) an operation related to the determination / acquisition / configuration / operation / decoding / encoding of the ACK signal may include In addition, in the following example, various information used by various STAs for determination/acquisition/configuration/computation/decoding/encoding of transmit/receive signals (for example, information related to fields/subfields/control fields/parameters/power, etc.) may be stored in the memories 112 and 122 of FIG. 1 .

The device/STA of the sub-view (a) of FIG. 1 described above may be modified as shown in the sub-view (b) of FIG. 1 . Hereinafter, the STAs 110 and 120 of the present specification will be described based on the sub-drawing (b) of FIG. 1 .

For example, the transceivers 113 and 123 shown in (b) of FIG. 1 may perform the same function as the transceivers shown in (a) of FIG. 1 . For example, the processing chips 114 and 124 illustrated in (b) of FIG. 1 may include processors 111 and 121 and memories 112 and 122 . The processors 111 and 121 and the memories 112 and 122 shown in (b) of FIG. 1 are the processors 111 and 121 and the memories 112 and 122 shown in (a) of FIG. ) can perform the same function.

As described below, a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile Mobile Subscriber Unit, user, user STA, network, base station, Node-B, access point (AP), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, Receiving Device, Transmitting Device, Receiving Apparatus, and/or Transmitting Apparatus means the STAs 110 and 120 shown in the sub-drawings (a)/(b) of FIG. ) may mean the processing chips 114 and 124 shown in FIG. That is, the technical features of the present specification may be performed on the STAs 110 and 120 shown in the sub-drawing (a)/(b) of FIG. 1, and the processing chip ( 114 and 124). For example, a technical feature in which a transmitting STA transmits a control signal is that the control signal generated by the processors 111 and 121 shown in the sub-drawing (a)/(b) of FIG. 1 is (a) of FIG. ) / (b) can be understood as a technical feature transmitted through the transceivers 113 and 123 shown in (b). Alternatively, the technical feature in which the transmitting STA transmits the control signal is a technical feature in which the control signal to be transmitted to the transceivers 113 and 123 is generated from the processing chips 114 and 124 shown in the sub-view (b) of FIG. can be understood

For example, the technical feature in which the receiving STA receives the control signal may be understood as the technical feature in which the control signal is received by the transceivers 113 and 123 shown in the sub-drawing (a) of FIG. 1 . Alternatively, the technical feature that the receiving STA receives the control signal is that the control signal received by the transceivers 113 and 123 shown in the sub-drawing (a) of FIG. 1 is the processor shown in (a) of FIG. 111, 121) can be understood as a technical feature obtained by. Alternatively, the technical feature that the receiving STA receives the control signal is that the control signal received by the transceivers 113 and 123 shown in the sub-view (b) of FIG. 1 is the processing chip shown in the sub-view (b) of FIG. It can be understood as a technical feature obtained by (114, 124).

Referring to (b) of FIG. 1 , software codes 115 and 125 may be included in the memories 112 and 122 . The software codes 115 and 125 may include instructions for controlling the operations of the processors 111 and 121 . Software code 115, 125 may be included in a variety of programming languages.

The processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and/or data processing devices. The processor may be an application processor (AP). For example, the processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 may include a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (Modem). and demodulator). For example, the processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 are a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, and a processor manufactured by Apple®. It may be an A series processor, a HELIOTM series processor manufactured by MediaTek®, an ATOMTM series processor manufactured by INTEL®, or a processor enhanced therewith.

In this specification, uplink may mean a link for communication from a non-AP STA to an AP STA, and an uplink PPDU/packet/signal may be transmitted through the uplink. In addition, in the present specification, downlink may mean a link for communication from an AP STA to a non-AP STA, and a downlink PPDU/packet/signal may be transmitted through the downlink.

2 is a conceptual diagram illustrating the structure of a wireless local area network (WLAN).

The upper part of FIG. 2 shows the structure of an infrastructure basic service set (BSS) of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.

Referring to the upper part of FIG. 2 , a WLAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, BSSs). The BSSs 200 and 205 are a set of APs and STAs, such as an access point (AP) 225 and a station 200-1 (STA1) that can communicate with each other through successful synchronization, and are not a concept indicating a specific area. The BSS 205 may include one or more combinable STAs 205 - 1 and 205 - 2 to one AP 230 .

The BSS may include at least one STA, APs 225 and 230 that provide a distribution service, and a distribution system DS 210 that connects a plurality of APs.

The distributed system 210 may implement an extended service set (ESS) 240 that is an extended service set by connecting several BSSs 200 and 205 . The ESS 240 may be used as a term indicating one network in which one or several APs are connected through the distributed system 210 . APs included in one ESS 240 may have the same service set identification (SSID).

The portal 220 may serve as a bridge connecting a wireless LAN network (IEEE 802.11) and another network (eg, 802.X).

In the BSS as shown in the upper part of FIG. 2 , a network between the APs 225 and 230 and a network between the APs 225 and 230 and the STAs 200 - 1 , 205 - 1 and 205 - 2 may be implemented. However, it may also be possible to establish a network and perform communication between STAs without the APs 225 and 230 . A network that establishes a network and performs communication even between STAs without the APs 225 and 230 is defined as an ad-hoc network or an independent basic service set (IBSS).

The lower part of FIG. 2 is a conceptual diagram illustrating the IBSS.

Referring to the lower part of FIG. 2 , the IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not include an AP, there is no centralized management entity that performs a centralized management function. That is, in the IBSS, the STAs 250-1, 250-2, 250-3, 255-4, and 255-5 are managed in a distributed manner. In IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and access to a distributed system is not allowed, so a self-contained network network) is formed.

3 is a diagram illustrating an example of a PPDU used in the IEEE standard.

As shown, in standards such as IEEE a/g/n/ac, various types of PHY protocol data units (PPDUs) are used. Specifically, the LTF and STF fields included a training signal, SIG-A and SIG-B included control information for the receiving station, and the data field included user data corresponding to MAC PDU/Aggregated MAC PDU (PSDU). included

3 also includes an example of an HE PPDU of the IEEE 802.11ax standard. The HE PPDU according to FIG. 3 is an example of a PPDU for multiple users. HE-SIG-B may be included only for multiple users, and the corresponding HE-SIG-B may be omitted from the PPDU for a single user.

As shown, HE-PPDU for multiple users (Multiple User; MU) is L-STF (legacy-short training field), L-LTF (legacy-long training field), L-SIG (legacy-signal), HE-SIG-A (high efficiency-signal A), HE-SIG-B (high efficiency-signal-B), HE-STF (high efficiency-short training field), HE-LTF (high efficiency-long training field) , a data field (or MAC payload) and a packet extension (PE) field. Each field may be transmitted during the illustrated time interval (ie, 4 or 8 μs, etc.).

Hereinafter, a resource unit (RU) used in the PPDU will be described. A resource unit may include a plurality of subcarriers (or tones). The resource unit may be used when transmitting a signal to a plurality of STAs based on the OFDMA technique. Also, even when a signal is transmitted to one STA, a resource unit may be defined. The resource unit may be used for STF, LTF, data field, and the like.

4 is a diagram illustrating an arrangement of a resource unit (RU) used on a 20 MHz band.

As shown in FIG. 4 , resource units (RUs) corresponding to different numbers of tones (ie, subcarriers) may be used to configure some fields of the HE-PPDU. For example, resources may be allocated in units of RUs shown for HE-STF, HE-LTF, and data fields.

As shown at the top of FIG. 4 , 26-units (ie, units corresponding to 26 tones) may be deployed. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and 5 tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, 7 DC tones are inserted into the center band, that is, the DC band, and 26-units corresponding to each of 13 tones may exist on the left and right sides of the DC band. In addition, 26-units, 52-units, and 106-units may be allocated to other bands. Each unit may be assigned for a receiving station, ie a user.

On the other hand, the RU arrangement of FIG. 4 is utilized not only in a situation for a plurality of users (MU), but also in a situation for a single user (SU). It is possible to use and in this case 3 DC tones can be inserted.

In the example of FIG. 4 , RUs of various sizes, ie, 26-RU, 52-RU, 106-RU, 242-RU, etc., have been proposed. Since the specific size of these RUs can be expanded or increased, this embodiment is not limited to the specific size of each RU (ie, the number of corresponding tones).

5 is a diagram illustrating an arrangement of a resource unit (RU) used on a 40 MHz band.

As in the example of FIG. 4, RUs of various sizes are used, and in the example of FIG. 5, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. may be used. In addition, 5 DC tones may be inserted into the center frequency, 12 tones are used as a guard band in the leftmost band of the 40 MHz band, and 11 tones are used in the rightmost band of the 40 MHz band. This can be used as a guard band.

Also, as shown, when used for a single user, 484-RU may be used. Meanwhile, the fact that the specific number of RUs can be changed is the same as in the example of FIG. 4 .

6 is a diagram illustrating an arrangement of resource units (RUs) used on an 80 MHz band.

As in the example of FIGS. 4 and 5, RUs of various sizes are used, in the example of FIG. 6, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. may be used. have. In addition, 7 DC tones may be inserted into the center frequency, 12 tones are used as a guard band in the leftmost band of the 80 MHz band, and 11 tones are used in the rightmost band of the 80 MHz band. This can be used as a guard band. In addition, 26-RU using 13 tones located on the left and right of the DC band can be used.

Also, as shown, when used for a single user, 996-RU may be used, and in this case, 5 DC tones may be inserted.

The RU described in this specification may be used for uplink (UL) communication and downlink (DL) communication. For example, when UL-MU communication solicited by a Trigger frame is performed, a transmitting STA (eg, AP) provides a first RU (eg, 26/52/106) to the first STA through a Trigger frame. /242-RU, etc.), and a second RU (eg, 26/52/106/242-RU, etc.) may be allocated to the second STA. Thereafter, the first STA may transmit a first trigger-based PPDU based on the first RU, and the second STA may transmit a second trigger-based PPDU based on the second RU. The first/second trigger-based PPDUs are transmitted to the AP in the same time interval.

For example, when the DL MU PPDU is configured, the transmitting STA (eg, AP) allocates a first RU (eg, 26/52/106/242-RU, etc.) to the first STA, and A second RU (eg, 26/52/106/242-RU, etc.) may be allocated to the 2 STAs. That is, the transmitting STA (eg, AP) may transmit the HE-STF, HE-LTF, and Data fields for the first STA through the first RU within one MU PPDU, and the second through the second RU. HE-STF, HE-LTF, and Data fields for 2 STAs may be transmitted.

Information on the arrangement of the RU may be signaled through HE-SIG-B.

7 shows the structure of the HE-SIG-B field.

As shown, the HE-SIG-B field 710 includes a common field 720 and a user-specific field 730 . The common field 720 may include information commonly applied to all users (ie, user STAs) receiving SIG-B. The user-individual field 730 may be referred to as a user-individual control field. The user-individual field 730 may be applied only to some of the plurality of users when the SIG-B is delivered to a plurality of users.

As shown in FIG. 7 , the common field 720 and the user-individual field 730 may be separately encoded.

The common field 720 may include N*8 bits of RU allocation information. For example, the RU allocation information may include information about the location of the RU. For example, when a 20 MHz channel is used as shown in FIG. 4, the RU allocation information may include information on which RUs (26-RU/52-RU/106-RU) are disposed in which frequency band. .

An example of a case in which the RU allocation information consists of 8 bits is as follows.

As in the example of FIG. 4 , a maximum of nine 26-RUs may be allocated to a 20 MHz channel. As shown in Table 1, when the RU allocation information of the common field 720 is set to "00000000", nine 26-RUs may be allocated to a corresponding channel (ie, 20 MHz). In addition, as shown in Table 1, when the RU allocation information of the common field 720 is set to "00000001", seven 26-RUs and one 52-RU are arranged in a corresponding channel. That is, in the example of FIG. 4 , 52-RUs may be allocated to the rightmost side, and seven 26-RUs may be allocated to the left side thereof.

An example of Table 1 shows only some of the RU locations that can be indicated by the RU allocation information.

For example, the RU allocation information may include an example of Table 2 below.

“01000y2y1y0” relates to an example in which 106-RU is allocated to the leftmost side of a 20 MHz channel, and 5 26-RUs are allocated to the right side thereof. In this case, a plurality of STAs (eg, User-STAs) may be allocated to the 106-RU based on the MU-MIMO technique. Specifically, a maximum of 8 STAs (eg, User-STAs) may be allocated to the 106-RU, and the number of STAs (eg, User-STAs) allocated to the 106-RU is 3-bit information (y2y1y0). ) is determined based on For example, when 3-bit information (y2y1y0) is set to N, the number of STAs (eg, User-STAs) allocated to the 106-RU based on the MU-MIMO technique may be N+1.

In general, a plurality of different STAs (eg, user STAs) may be allocated to a plurality of RUs. However, a plurality of STAs (eg, user STAs) may be allocated to one RU having a specific size (eg, 106 subcarriers) or more based on the MU-MIMO technique.

As shown in FIG. 7 , the user-individual field 730 may include a plurality of user fields. As described above, the number of STAs (eg, user STAs) allocated to a specific channel may be determined based on the RU allocation information of the common field 720 . For example, when the RU allocation information of the common field 720 is “00000000”, one user STA may be allocated to each of the nine 26-RUs (that is, a total of nine user STAs are allocated). That is, a maximum of 9 user STAs may be allocated to a specific channel through the OFDMA technique. In other words, up to 9 user STAs may be allocated to a specific channel through the non-MU-MIMO technique.

For example, when the RU allocation is set to “01000y2y1y0”, a plurality of user STAs are allocated to the 106-RU disposed on the left-most side through the MU-MIMO technique, and five 26-RUs disposed on the right side have Five user STAs may be allocated through the non-MU-MIMO technique. This case is embodied through an example of FIG. 8 .

8 shows an example in which a plurality of user STAs are allocated to the same RU through the MU-MIMO technique.

For example, when RU allocation is set to “01000010” as shown in FIG. 7, based on Table 2, 106-RU is allocated to the leftmost side of a specific channel and 5 26-RUs are allocated to the right side of the channel. can In addition, a total of three user STAs may be allocated to the 106-RU through the MU-MIMO technique. As a result, since a total of 8 User STAs are allocated, the user-individual field 730 of HE-SIG-B may include 8 User fields.

Eight user fields may be included in the order shown in FIG. 8 . Also, as shown in FIG. 7 , two user fields may be implemented as one user block field.

The User field shown in FIGS. 7 and 8 may be configured based on two formats. That is, the user field related to the MU-MIMO technique may be configured in the first format, and the user field related to the non-MU-MIMO technique may be configured in the second format. Referring to the example of FIG. 8 , User fields 1 to 3 may be based on a first format, and User fields 4 to 8 may be based on a second format. The first format or the second format may include bit information of the same length (eg, 21 bits).

Each user field may have the same size (eg, 21 bits). For example, the user field of the first format (the format of the MU-MIMO technique) may be configured as follows.

For example, the first bit (eg, B0-B10) in the user field (ie, 21 bits) is identification information of the user STA to which the corresponding user field is allocated (eg, STA-ID, partial AID, etc.) may include. In addition, the second bit (eg, B11-B14) in the user field (ie, 21 bits) may include information about spatial configuration. Specifically, examples of the second bits (ie, B11-B14) may be as shown in Tables 3 to 4 below.

As shown in Table 3 and/or Table 4, the second bit (ie, B11-B14) may include information about the number of spatial streams allocated to a plurality of user STAs allocated according to the MU-MIMO technique. have. For example, when three user STAs are allocated to 106-RU based on the MU-MIMO technique as shown in FIG. 8, N_user is set to "3", and accordingly, as shown in Table 3, N_STS[1], Values of N_STS[2] and N_STS[3] may be determined. For example, when the value of the second bits B11-B14 is “0011”, N_STS[1]=4, N_STS[2]=1, N_STS[3]=1 may be set. That is, in the example of FIG. 8 , four spatial streams may be allocated to user field 1, one spatial stream may be allocated to user field 2, and one spatial stream may be allocated to user field 3 in the example of FIG.

As an example of Table 3 and/or Table 4, information about the number of spatial streams for a user STA (ie, the second bit, B11-B14) may consist of 4 bits. In addition, information on the number of spatial streams (ie, second bits, B11-B14) for a user STA may support up to 8 spatial streams. In addition, information on the number of spatial streams (ie, the second bit, B11-B14) may support up to four spatial streams for one user STA.

In addition, the third bit (ie, B15-18) in the user field (ie, 21 bits) may include modulation and coding scheme (MCS) information. The MCS information may be applied to a data field in the PPDU including the corresponding SIG-B.

MCS, MCS information, MCS index, MCS field, etc. used in this specification may be indicated by a specific index value. For example, MCS information may be indicated by index 0 to index 11. MCS information includes information about a constellation modulation type (eg, BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.), and a coding rate (eg, 1/2, 2/ 3, 3/4, 5/6, etc.). Information about a channel coding type (eg, BCC or LDPC) may be excluded from the MCS information.

Also, the fourth bit (ie, B19) in the User field (ie, 21 bits) may be a Reserved field.

In addition, a fifth bit (ie, B20) in the user field (ie, 21 bits) may include information about a coding type (eg, BCC or LDPC). That is, the fifth bit (ie, B20) may include information on the type of channel coding (eg, BCC or LDPC) applied to the data field in the PPDU including the corresponding SIG-B.

The above-described example relates to the User Field of the first format (the format of the MU-MIMO technique). An example of the user field of the second format (the format of the non-MU-MIMO technique) is as follows.

The first bit (eg, B0-B10) in the user field of the second format may include identification information of the user STA. In addition, the second bit (eg, B11-B13) in the user field of the second format may include information about the number of spatial streams applied to the corresponding RU. In addition, the third bit (eg, B14) in the user field of the second format may include information on whether a beamforming steering matrix is applied. A fourth bit (eg, B15-B18) in the user field of the second format may include modulation and coding scheme (MCS) information. In addition, a fifth bit (eg, B19) in the user field of the second format may include information on whether Dual Carrier Modulation (DCM) is applied. In addition, the sixth bit (ie, B20) in the user field of the second format may include information about a coding type (eg, BCC or LDPC).

9 shows an operation according to UL-MU. As shown, the transmitting STA (eg, AP) may perform channel access through contending (ie, backoff operation) and transmit a trigger frame 930 . That is, the transmitting STA (eg, AP) may transmit the PPDU including the Trigger Frame 930 . When a PPDU including a trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

The TB PPDUs 941 and 942 are transmitted in the same time zone, and may be transmitted from a plurality of STAs (eg, user STAs) whose AIDs are indicated in the trigger frame 930 . The ACK frame 950 for the TB PPDU may be implemented in various forms.

10 shows an example of a channel used/supported/defined in the 2.4 GHz band.

The 2.4 GHz band may be referred to as another name such as a first band (band). Also, the 2.4 GHz band may mean a frequency region in which channels having a center frequency adjacent to 2.4 GHz (eg, channels having a center frequency within 2.4 to 2.5 GHz) are used/supported/defined.

The 2.4 GHz band may contain multiple 20 MHz channels. 20 MHz in the 2.4 GHz band may have multiple channel indices (eg, indices 1 to 14). For example, a center frequency of a 20 MHz channel to which channel index 1 is allocated may be 2.412 GHz, a center frequency of a 20 MHz channel to which channel index 2 is allocated may be 2.417 GHz, and 20 MHz to which channel index N is allocated. The center frequency of the channel may be (2.407 + 0.005*N) GHz. The channel index may be referred to by various names such as a channel number. Specific values of the channel index and the center frequency may be changed.

10 exemplarily shows four channels in the 2.4 GHz band. The illustrated first frequency region 1010 to fourth frequency region 1040 may each include one channel. For example, the first frequency domain 1010 may include channel 1 (a 20 MHz channel having index 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency domain 1020 may include channel 6 . In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency domain 1030 may include channel 11 . In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency domain 1040 may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

11 shows an example of a channel used/supported/defined within the 5 GHz band.

The 5 GHz band may be referred to as another name such as a second band/band. The 5 GHz band may mean a frequency region in which channels having a center frequency of 5 GHz or more and less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include a plurality of channels between 4.5 GHz and 5.5 GHz. The specific numerical values shown in FIG. 11 may be changed.

The plurality of channels in the 5 GHz band include UNII (Unlicensed National Information Infrastructure)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may contain frequency domains called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

A plurality of channels may be set in the 5 GHz band, and the bandwidth of each channel may be variously set to 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency region/range in UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain/range may be divided into 4 channels through the 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain/range may be divided into two channels through the 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain/range may be divided into one channel through the 160 MHz frequency domain.

12 shows an example of a channel used/supported/defined within the 6 GHz band.

The 6 GHz band may be referred to as another name such as a third band/band. The 6 GHz band may mean a frequency region in which channels having a center frequency of 5.9 GHz or higher are used/supported/defined. The specific numerical values shown in FIG. 12 may be changed.

For example, the 20 MHz channel of FIG. 12 may be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 may have an index 1 (or, a channel index, a channel number, etc.), and a center frequency of 5.945 GHz may be allocated. That is, the center frequency of the channel index N may be determined to be (5.940 + 0.005*N) GHz.

Accordingly, the index (or channel number) of the 20 MHz channel of FIG. 12 is 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. In addition, according to the above-mentioned (5.940 + 0.005*N) GHz rule, the index of the 40 MHz channel of FIG. 12 is 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

Although 20, 40, 80, and 160 MHz channels are illustrated in the example of FIG. 12 , a 240 MHz channel or a 320 MHz channel may be additionally added.

Hereinafter, the PPDU transmitted/received by the STA of the present specification will be described.

13 shows an example of a PPDU used in this specification.

The PPDU of FIG. 13 may be called by various names such as an EHT PPDU, a transmission PPDU, a reception PPDU, a first type or an Nth type PPDU. For example, in the present specification, a PPDU or an EHT PPDU may be referred to as various names such as a transmission PPDU, a reception PPDU, a first type or an Nth type PPDU. In addition, the EHT PPU may be used in an EHT system and/or a new WLAN system in which the EHT system is improved.

The PPDU of FIG. 13 may represent some or all of the PPDU types used in the EHT system. For example, the example of FIG. 13 may be used for both a single-user (SU) mode and a multi-user (MU) mode. In other words, the PPDU of FIG. 13 may be a PPDU for one receiving STA or a plurality of receiving STAs. When the PPDU of FIG. 13 is used for a trigger-based (TB) mode, the EHT-SIG of FIG. 13 may be omitted. In other words, the STA that has received the Trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU in which the EHT-SIG is omitted in the example of FIG. 13 .

In FIG. 13 , L-STF to EHT-LTF may be referred to as a preamble or a physical preamble, and may be generated/transmitted/received/acquired/decoded in a physical layer.

The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields of FIG. 13 is set to 312.5 kHz, and the subcarrier spacing of the EHT-STF, EHT-LTF, and Data fields may be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields is displayed in units of 312.5 kHz, EHT-STF, EHT-LTF, The tone index (or subcarrier index) of the Data field may be displayed in units of 78.125 kHz.

In the PPDU of FIG. 13, L-LTF and L-STF may be the same as the conventional fields.

The L-SIG field of FIG. 13 may include, for example, 24-bit bit information. For example, 24-bit information may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity bit, and a 6-bit Tail bit. For example, the 12-bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, when the PPDU is a non-HT, HT, VHT PPDU or an EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, when the PPDU is an HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 +2". In other words, for non-HT, HT, VHT PPDU or EHT PPDU, the value of the Length field may be determined as a multiple of 3, and for the HE PPDU, the value of the Length field may be "a multiple of 3 + 1" or "a multiple of 3" +2".

For example, the transmitting STA may apply BCC encoding based on a code rate of 1/2 to 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain a 48-bit BCC encoding bit. BPSK modulation may be applied to 48-bit coded bits to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to positions excluding pilot subcarriers {subcarrier indexes -21, -7, +7, +21} and DC subcarriers {subcarrier index 0}. As a result, 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. have. The transmitting STA may additionally map signals of {-1, -1, -1, 1} to the subcarrier indexes {-28, -27, +27, +28}. The above signal may be used for channel estimation in the frequency domain corresponding to {-28, -27, +27, +28}.

The transmitting STA may generate an RL-SIG that is generated in the same way as the L-SIG. For RL-SIG, BPSK modulation may be applied. The receiving STA may know that the received PPDU is an HE PPDU or an EHT PPDU based on the existence of the RL-SIG.

A U-SIG (Universal SIG) may be inserted after the RL-SIG of FIG. 13 . The U-SIG may be referred to by various names such as a first SIG field, a first SIG, a first type SIG, a control signal, a control signal field, and a first (type) control signal.

The U-SIG may include information of N bits, and may include information for identifying the type of the EHT PPDU. For example, the U-SIG may be configured based on two symbols (eg, two consecutive OFDM symbols). Each symbol (eg, OFDM symbol) for U-SIG may have a duration of 4 μs. Each symbol of the U-SIG may be used to transmit 26-bit information. For example, each symbol of the U-SIG may be transmitted/received based on 52 data tones and 4 pilot tones.

For example, A-bit information (eg, 52 un-coded bits) may be transmitted through the U-SIG (or U-SIG field), and the first symbol of the U-SIG is the first of the total A-bit information. X-bit information (eg, 26 un-coded bits) is transmitted, and the second symbol of U-SIG can transmit the remaining Y-bit information (eg, 26 un-coded bits) of the total A-bit information. have. For example, the transmitting STA may obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA may generate a 52-coded bit by performing convolutional encoding (ie, BCC encoding) based on a rate of R=1/2, and may perform interleaving on the 52-coded bit. The transmitting STA may generate 52 BPSK symbols allocated to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. One U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, except for DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) excluding pilot tones -21, -7, +7, and +21 tones.

For example, A-bit information (eg, 52 un-coded bits) transmitted by U-SIG includes a CRC field (eg, a 4-bit long field) and a tail field (eg, a 6-bit long field). ) may be included. The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on the remaining 16 bits except for the CRC/tail field in the 26 bits allocated to the first symbol of the U-SIG and the second symbol, and may be generated based on the conventional CRC calculation algorithm. can Also, the tail field may be used to terminate the trellis of the convolutional decoder, and may be set to, for example, “000000”.

A bit information (eg, 52 un-coded bits) transmitted by U-SIG (or U-SIG field) may be divided into version-independent bits and version-dependent bits. For example, the size of version-independent bits may be fixed or variable. For example, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the version-dependent bits may be referred to by various names such as a first control bit and a second control bit.

For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmission/reception PPDU. For example, the first value of the 3-bit PHY version identifier may indicate that the transmission/reception PPDU is an EHT PPDU. In other words, when transmitting the EHT PPDU, the transmitting STA may set the 3-bit PHY version identifier as the first value. In other words, the receiving STA may determine that the receiving PPDU is an EHT PPDU based on the PHY version identifier having the first value.

For example, the version-independent bits of the U-SIG may include a 1-bit UL/DL flag field. A first value of the 1-bit UL/DL flag field relates to UL communication, and a second value of the UL/DL flag field relates to DL communication.

For example, the version-independent bits of the U-SIG may include information about the length of the TXOP and information about the BSS color ID.

For example, when the EHT PPDU is divided into various types (eg, various types such as EHT PPDU related to SU mode, EHT PPDU related to MU mode, EHT PPDU related to TB mode, EHT PPDU related to Extended Range transmission) , information on the type of the EHT PPDU may be included in the version-dependent bits of the U-SIG.

For example, the U-SIG is 1) a bandwidth field including information about bandwidth, 2) a field including information about an MCS technique applied to the EHT-SIG, 3) dual subcarrier modulation to the EHT-SIG (dual An indication field including information on whether subcarrier modulation, DCM) technique is applied, 4) a field including information on the number of symbols used for EHT-SIG, 5) EHT-SIG is generated over the entire band It may include a field including information on whether or not it is, 6) a field including information about the type of EHT-LTF/STF, and 7) information about a field indicating the length of the EHT-LTF and the CP length.

Preamble puncturing may be applied to the PPDU of FIG. 13 . The preamble puncturing refers to applying puncturing to some bands (eg, the secondary 20 MHz band) among the entire bands of the PPDU. For example, when an 80 MHz PPDU is transmitted, the STA may apply puncturing to the secondary 20 MHz band among the 80 MHz band and transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

For example, the pattern of preamble puncturing may be set in advance. For example, when the first puncturing pattern is applied, puncturing may be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing may be applied only to any one of the two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing may be applied only to the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, the primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) is present and does not belong to the primary 40 MHz band. Puncture may be applied to at least one 20 MHz channel that is not

Information on preamble puncturing applied to the PPDU may be included in the U-SIG and/or the EHT-SIG. For example, the first field of the U-SIG includes information on the contiguous bandwidth of the PPDU, and the second field of the U-SIG includes information on the preamble puncturing applied to the PPDU. have.

For example, U-SIG and EHT-SIG may include information about preamble puncturing based on the following method. When the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be individually configured in units of 80 MHz. For example, when the bandwidth of the PPDU is 160 MHz, the corresponding PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG includes information about the 160 MHz bandwidth, and the second field of the first U-SIG includes information about the preamble puncturing applied to the first 80 MHz band (that is, the preamble information about the puncturing pattern). In addition, the first field of the second U-SIG includes information about the 160 MHz bandwidth, and the second field of the second U-SIG includes information about the preamble puncturing applied to the second 80 MHz band (ie, preamble puncture). information about processing patterns). On the other hand, the EHT-SIG subsequent to the first U-SIG may include information on preamble puncturing applied to the second 80 MHz band (that is, information on the preamble puncturing pattern), and in the second U-SIG The successive EHT-SIG may include information about preamble puncturing applied to the first 80 MHz band (ie, information about a preamble puncturing pattern).

Additionally or alternatively, the U-SIG and the EHT-SIG may include information on preamble puncturing based on the following method. The U-SIG may include information on preamble puncturing for all bands (ie, information on preamble puncturing patterns). That is, the EHT-SIG does not include information about the preamble puncturing, and only the U-SIG may include information about the preamble puncturing (ie, information about the preamble puncturing pattern).

The U-SIG may be configured in units of 20 MHz. For example, when an 80 MHz PPDU is configured, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth may include different U-SIGs.

The EHT-SIG of FIG. 13 may include control information for the receiving STA. The EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 μs. Information on the number of symbols used for the EHT-SIG may be included in the U-SIG.

The EHT-SIG may include technical features of the HE-SIG-B described with reference to FIGS. 7 to 8 . For example, the EHT-SIG may include a common field and a user-specific field, as in the example of FIG. 7 . The common field of the EHT-SIG may be omitted, and the number of user-individual fields may be determined based on the number of users.

As in the example of FIG. 7 , the common field of the EHT-SIG and the user-individual field of the EHT-SIG may be individually coded. One user block field included in the user-individual field may contain information for two users, but the last user block field included in the user-individual field is for one user. It is possible to include information. In the EHT standard, the user block field may be called by various names. For example, names such as user encoding block field and user field may be used. That is, one user block field of the EHT-SIG may include a maximum of two user fields. As in the example of FIG. 8 , each user field may be related to MU-MIMO assignment or may be related to non-MU-MIMO assignment.

As in the example of FIG. 7, the common field of EHT-SIG may include a CRC bit and a Tail bit, the length of the CRC bit may be determined as 4 bits, and the length of the Tail bit may be determined as 6 bits and set to '000000'. can be set.

As in the example of FIG. 7 , the common field of the EHT-SIG may include RU allocation information. The RU allocation information may refer to information about a location of an RU to which a plurality of users (ie, a plurality of receiving STAs) are allocated. As in Table 1, RU allocation information may be configured in units of 8 bits (or N bits).

An example of Tables 5 to 7 is an example of 8-bit (or N-bit) information for various RU allocation. Indexes indicated in each table may be changed, some entries in Tables 5 to 7 may be omitted, and entries not indicated may be added.

Examples of Tables 5 to 7 relate to information about the location of an RU allocated to a 20 MHz band. For example, 'index 0' of Table 5 may be used in a situation in which nine 26-RUs are individually allocated (eg, a situation in which nine 26-RUs shown in FIG. 4 are individually allocated).

On the other hand, in the EHT system, it is possible to allocate a plurality of RUs to one STA, for example, in 'index 60' in Table 6, one 26-RU is one user (that is, on the leftmost side of the 20 MHz band) receiving STA), and one 26-RU and one 52-RU are allocated for another user (ie, receiving STA) to the right of it, and 5 26-RUs are individually allocated to the right of it. can be

A mode in which the common field of EHT-SIG is omitted may be supported. The mode in which the common field of EHT-SIG is omitted may be called compressed mode. When compressed mode is used, a plurality of users (ie, a plurality of receiving STAs) of the EHT PPDU may decode the PPDU (eg, a data field of the PPDU) based on non-OFDMA. That is, a plurality of users of the EHT PPDU may decode a PPDU (eg, a data field of the PPDU) received through the same frequency band. On the other hand, when the non-compressed mode is used, a plurality of users of the EHT PPDU may decode the PPDU (eg, the data field of the PPDU) based on OFDMA. That is, a plurality of users of the EHT PPDU may receive the PPDU (eg, a data field of the PPDU) through different frequency bands.

The EHT-SIG may be configured based on various MCS techniques. As described above, information related to the MCS technique applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be configured based on the DCM technique. For example, among the N data tones (eg, 52 data tones) allocated for the EHT-SIG, a first modulation scheme is applied to a continuous half tone, and a second modulation scheme is applied to the remaining consecutive half tones. technique can be applied. That is, the transmitting STA modulates specific control information into a first symbol based on the first modulation scheme and allocates to consecutive half tones, modulates the same control information into a second symbol based on the second modulation scheme, and modulates the remaining consecutive tones. can be allocated to half the tone. As described above, information (eg, 1-bit field) related to whether the DCM technique is applied to the EHT-SIG may be included in the U-SIG.

The EHT-STF of FIG. 13 may be used to improve automatic gain control estimation in a multiple input multiple output (MIMO) environment or an OFDMA environment. The EHT-LTF of FIG. 13 may be used to estimate a channel in a MIMO environment or an OFDMA environment.

The PPDU of FIG. 13 (ie, EHT-PPDU) may be configured based on the examples of FIGS. 4 and 5 .

For example, an EHT PPDU transmitted on a 20 MHz band, that is, a 20 MHz EHT PPDU may be configured based on the RU of FIG. 4 . That is, the location of the RU of the EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in FIG. 4 .

The EHT PPDU transmitted on the 40 MHz band, that is, the 40 MHz EHT PPDU may be configured based on the RU of FIG. 5 . That is, the location of the RU of the EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in FIG. 5 .

Since the RU location of FIG. 5 corresponds to 40 MHz, if the pattern of FIG. 5 is repeated twice, a tone-plan for 80 MHz may be determined. That is, the 80 MHz EHT PPDU may be transmitted based on a new tone-plan in which the RU of FIG. 5 is repeated twice instead of the RU of FIG. 6 .

When the pattern of FIG. 5 is repeated twice, 23 tones (ie, 11 guard tones + 12 guard tones) may be configured in the DC region. That is, the tone-plan for the 80 MHz EHT PPDU allocated based on OFDMA may have 23 DC tones. In contrast, 80 MHz EHT PPDU (ie, non-OFDMA full bandwidth 80 MHz PPDU) allocated on the basis of Non-OFDMA is configured based on 996 RUs and consists of 5 DC tones, 12 left guard tones, and 11 right guard tones. may include.

The tone-plan for 160/240/320 MHz may be configured in the form of repeating the pattern of FIG. 5 several times.

The PPDU of FIG. 13 may be determined (or identified) as an EHT PPDU based on the following method.

The receiving STA may determine the type of the receiving PPDU as an EHT PPDU based on the following items. For example, 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) the RL-SIG where the L-SIG of the received PPDU is repeated is detected, and 3) the L-SIG of the received PPDU is Length When a result of applying “modulo 3” to the field value is detected as “0”, the received PPDU may be determined as an EHT PPDU. When it is determined that the received PPDU is an EHT PPDU, the receiving STA determines the type of the EHT PPDU (eg, SU/MU/Trigger-based/Extended Range type) based on bit information included in the symbols after the RL-SIG of FIG. 13 . ) can be detected. In other words, the receiving STA 1) the first symbol after the L-LTF signal that is BSPK, 2) RL-SIG that is continuous to the L-SIG field and is the same as the L-SIG, 3) the result of applying “modulo 3” is “ L-SIG including a Length field set to 0”, and 4) based on the 3-bit PHY version identifier (eg, PHY version identifier having a first value) of the above-described U-SIG, receive PPDU It can be determined as an EHT PPDU.

For example, the receiving STA may determine the type of the received PPDU as the HE PPDU based on the following items. For example, 1) the first symbol after the L-LTF signal is BPSK, 2) RL-SIG where L-SIG is repeated is detected, 3) “modulo 3” is applied to the Length value of L-SIG. When the result is detected as “1” or “2”, the received PPDU may be determined as an HE PPDU.

For example, the receiving STA may determine the type of the received PPDU as non-HT, HT, and VHT PPDU based on the following items. For example, if 1) the first symbol after the L-LTF signal is BPSK, and 2) RL-SIG in which L-SIG is repeated is not detected, the received PPDU is determined to be non-HT, HT and VHT PPDU. can

In the following example, (transmit/receive/uplink/down) signal, (transmit/receive/up/down) frame, (transmit/receive/up/down) packet, (transmit/receive/up/down) data unit, ( A signal indicated by transmission/reception/uplink/downlink) data, etc. may be a signal transmitted/received based on the PPDU of FIG. 13 . The PPDU of FIG. 13 may be used to transmit and receive various types of frames. For example, the PPDU of FIG. 13 may be used for a control frame. Examples of the control frame may include request to send (RTS), clear to send (CTS), Power Save-Poll (PS-Poll), BlockACKReq, BlockAck, Null Data Packet (NDP) announcement, and Trigger Frame. For example, the PPDU of FIG. 13 may be used for a management frame. An example of the management frame may include a Beacon frame, (Re-)Association Request frame, (Re-)Association Response frame, Probe Request frame, and Probe Response frame. For example, the PPDU of FIG. 13 may be used for a data frame. For example, the PPDU of FIG. 13 may be used to simultaneously transmit at least two or more of a control frame, a management frame, and a data frame.

14 shows a modified example of a transmitting apparatus and/or a receiving apparatus of the present specification.

Each device/STA of the sub-drawings (a)/(b) of FIG. 1 may be modified as shown in FIG. 14 . The transceiver 630 of FIG. 14 may be the same as the transceivers 113 and 123 of FIG. 1 . The transceiver 630 of FIG. 14 may include a receiver and a transmitter.

The processor 610 of FIG. 14 may be the same as the processors 111 and 121 of FIG. 1 . Alternatively, the processor 610 of FIG. 14 may be the same as the processing chips 114 and 124 of FIG. 1 .

The memory 150 of FIG. 14 may be the same as the memories 112 and 122 of FIG. 1 . Alternatively, the memory 150 of FIG. 14 may be a separate external memory different from the memories 112 and 122 of FIG. 1 .

Referring to FIG. 14 , the power management module 611 manages power for the processor 610 and/or the transceiver 630 . The battery 612 supplies power to the power management module 611 . The display 613 outputs the result processed by the processor 610 . Keypad 614 receives input to be used by processor 610 . A keypad 614 may be displayed on the display 613 . SIM card 615 may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) used to identify and authenticate subscribers in mobile phone devices, such as mobile phones and computers, and keys associated therewith. .

Referring to FIG. 14 , the speaker 640 may output a sound related result processed by the processor 610 . Microphone 641 may receive sound related input to be used by processor 610 .

15 is a diagram illustrating an arrangement of resource units (RUs) used on an 80 MHz band. The arrangement of resource units (RU) used in this specification may be variously changed. For example, the arrangement of resource units (RUs) used on the 80 MHz band may be variously changed. For example, the arrangement of resource units (RU) used on the 80 MHz band may be configured based on FIG. 15 instead of FIG. 6 .

Configuration of EHT PPDU

To support a transmission method based on the EHT standard, a new frame format may be used. When transmitting a signal through the 2.4/5/6 GHz band using the new frame format, convention Wi-Fi receivers (or STAs) (eg, 802.11n) as well as a receiver (receiver) supported by the EHT standard Receivers according to the /ac/ax standard) may also receive the EHT signal transmitted through the 2.4/5/6 GHz band.

The preamble of the PPDU based on the EHT standard may be set in various ways. Hereinafter, an embodiment in which a preamble of a PPDU based on the EHT standard is configured may be described. Hereinafter, a PPDU based on the EHT standard may be described as an EHT PPDU. However, the EHT PPDU is not limited to the EHT standard. The EHT PPDU may include not only the 802.11be standard (ie, the EHT standard), but also a PPDU based on a new standard obtained by improving/evolving/extending the 802.11be standard.

16 shows an example of an EHT PPDU.

Referring to FIG. 16 , the EHT PPDU 1600 may include an L-part 1610 and an EHT-part 1620 . The EHT PPDU 1600 may be configured in a format to support backward compatibility. In addition, the EHT PPDU 1600 may be transmitted to a single STA (single STA) and/or multiple STAs. The EHT PPDU 1600 may be an example of an EHT standard MU-PPDU.

EHT PPDU 1600 is a legacy STA (STA according to the 802.11n / ac / ax standard) for coexistence or backward compatibility with the EHT-part (1620) for the L-part (1610) first. It may be configured in a structure to be transmitted. For example, the L-part 1610 may include L-STF, L-LTF, and L-SIG. For example, phase rotation may be applied to the L-part 1610 .

According to an embodiment, the EHT part 1620 may include RL-SIG, U-SIG 1621, EHT-SIG 1622, EHT-STF, EHT-LTF and data fields. Similar to the 11ax standard, the RL-SIG may be included in the EHT part 1620 for reliability and range extension of the L-SIG. The RL-SIG may be transmitted immediately after the L-SIG, and the L-SIG may be configured to be repeated.

For example, four additional sub-carriers may be applied to L-SIG and RL-SIG. The extra sub-carriers may be configured as [-28, -27, 27, 28]. The extra sub-carriers may be modulated in a BPSK scheme. In addition, coefficients of [-1 -1 -1 1] may be mapped to the extra subcarriers.

For example, the EHT-LTF may be configured as one of 1x EHT-LTF, 2x EHT-LTF, or 4x EHT-LTF. The EHT standard may support EHT-LTF for 16 spatial streams.

Each field in FIG. 16 may be the same as each field described in FIG. 13 .

Hereinafter, the first control signal field (eg, U-SIG field) and the second control signal field (eg, EHT-SIG field) will be described in detail.

Control information not included in the first control signal field (eg, U-SIG field) may be referred to by various names such as overflowed information or overflow information. The second control signal field (eg, EHT-SIG field) may include a common field and a user specific field. Each of the common field and the user specific field may include at least one encoding block (eg, a binary convolutional code (BCC) encoding block). One encoding block may be transmitted/received through at least one symbol, and one encoding block is not necessarily transmitted through one symbol. Meanwhile, one symbol for transmitting the encoding block may have a symbol length of 4 μs.

The transmission/reception PPDU proposed in this specification may be used for communication for at least one user. For example, the technical features of the present specification may be applied to an MU-PPDU (eg, EHT MU PPDU) according to the 11be standard.

17 shows an example of the first control signal field or the U-SIG field of the present specification.

As shown, the first control signal field (eg, U-SIG field) may include a version independent field 1710 and a version dependent field 1720 . For example, the version independent field 1710 may include control information that is continuously included irrespective of the wireless LAN version (eg, next-generation standards of IEEE 802.11be and 11be). For example, the version dependent field 1720 may include control information dependent on the corresponding Version (eg, IEEE 802.11be standard).

For example, the version independent field 1710 may include information related to a 3-bit version identifier indicating a Wi-Fi version after 11be and 11be, a 1-bit DL/UL field BSS color, and/or TXOP duration. For example, the version dependent field 1720 may include information related to PPDU format type and/or Bandwidth, and MCS.

For example, in the first control signal field (eg, U-SIG field) shown in FIG. 17 , two symbols (eg, two consecutive 4 μs-long symbols) may be jointly encoded. In addition, the field of FIG. 17 may be configured based on 52 data tones and 4 pilot tones for each 20 MHz band/channel. In addition, the field of FIG. 17 may be modulated in the same manner as the HE-SIG-A of the conventional 11ax standard. In other words, the field of FIG. 17 may be modulated based on the BPSK 1/2 code rate.

For example, the second control signal field (eg, EHT-SIG field) may be divided into a common field and a user specific field, and may be encoded based on various MCS levels. For example, the Common field may include indication information related to a spatial stream used in a transmission/reception PPDU (eg, a data field) and indication information related to an RU. For example, the user specific field may include ID information used by at least one specific user (or receiving STA), MCS, and indication information related to coding. In other words, the user specific field includes decoding information (eg, corresponding to the data field transmitted through at least one RU indicated by an RU allocation sub-field included in the common field). STA ID information assigned to the RU, MSC information, and/or channel coding type/rate information).

The above-described first control signal field or U-SIG field may be transmitted through two consecutive symbols. In other words, the U-SIG field may include a first U-SIG signal transmitted through a first symbol and a second U-SIG signal transmitted through a second symbol. Each of the first U-SIG signal and the second U-SIG signal may be configured based on 26-bit control information.

For example, the first U-SIG signal may be configured based on 26-bit control information including B0 bits to B25 bits. An example of the B0 bit to the B25 bit for the first U-SIG signal is as follows. The fields (or subfields) listed in Table 8 may belong to the Version independent category.

As shown in Table 8, bits B0 to B2 of the first U-SIG signal may include information related to the PHY version of the PPDU through 3-bit information. Bits B3 to B5 of the first U-SIG signal may include information about the bandwidth of the transmission/reception PPDU through 3-bit information. Bit B6 of the first U-SIG signal may include information on whether the transmission/reception PPDU is for UL communication or DL communication. Bits B7 to B12 of the first U-SIG signal may include information about the BSS Color ID of the transmission/reception PPDU. The information on the BSS Color ID may be used to identify whether the transmission/reception PPDU is an intra-PPDU or an inter-PPDU. Bits B13 to B19 of the first U-SIG signal may include information on the duration of the TXOP of the transmission/reception PPDU. Bits B20 to B24 of the first U-SIG signal are reserved bits and may be ignored by the receiving STA. Bit B25 of the first U-SIG signal is a reserved bit and may be related to termination of a reception operation of the receiving STA.

Bit Field Number of bits B0 - B2 PHY Version Identifier 3 B3 - B5 Bandwidth 3 B6 UL/DL One B7 - B12 BSS Color 6 B13 - B19 TXOP 7 B20 - B24 Disregard 5 B25 Validate One

For example, the second U-SIG signal may be configured based on 26-bit control information including B0 bits to B25 bits. An example of the B0 bit to the B25 bit for the second U-SIG signal is as follows. Bits B0 to B15 among the fields (or subfields) listed in Table 9 may belong to the version dependent category. Bits B0 to B1 of the second U-SIG signal determine whether the transmit/receive PPDU is used for DL OFDMA communication. , whether it is used for DL MU-MIMO communication, or whether it is used for SU or NDP communication, and the like. B2 bit and B8 bit of the second U-SIG signal are reserved bits, and may be related to termination of a reception operation of the receiving STA. Bits B3 to B7 of the second U-SIG signal may include information on a puncturing pattern applied to a transmission/reception PPDU. Bits B9 to B10 of the second U-SIG signal may include information for an MCS technique applied to the EHT-SIG field. Bits B11 to B15 of the second U-SIG signal may include information about the number of symbols used to transmit the EHT-SIG field. Bits B16 to B19 of the second U-SIG signal may include a CRC field for the U-SIG field. The CRC field may be calculated based on B0 bits to B25 bits of the first U-SIG signal and B0 bits to B15 bits of the second U-SIG signal. Bit B25 of the second U-SIG signal may be all set to 0 as a tail bit.

Bit Field Number of bits B0 - B1 PPDU Type And Compression Mode 2 B2 Validate One B3-B7 Punctured Channel Information 5 B8 Validate One B9 - B10 EHT-SIG MCS 2 B11 - B15 Number Of EHT-SIG Symbols 5 B16-B19 CRC 4 B20-B25 Tail 6

The second control signal field (eg, the EHT-SIG) may be divided into a common field and a user specific field. For example, the common field may include RU allocation information. For example, the user specific field may include at least one user encoding block field or a user field including information on a user (ie, a receiving STA). The EHT-SIG may be transmitted through an EHT-SIG content channel composed of 20 MHz segments. That is, one EHT-SIG content channel may be transmitted through a 20 MHz sub-channel. For example, a PPDU having a bandwidth of 80 MHz or more may be transmitted through two EHT-SIG content channels. For example, the two EHT-SIG content channels may be referred to as EHT CC1 and EHT CC2. For example, when a PPDU is transmitted through 160 MHz, an EHT-SIG having different information may be transmitted for each of two 80 MHz bands. EHT-SIG transmitted through any one of the 80 MHz bands may be transmitted through EHT CC1 and EHT CC2.

Hereinafter, technical features related to the LTF signal of the present specification will be described.

18 illustrates a general technique for generating an LTF signal.

The example of FIG. 18 may be equally applied to a high throughput (HT) system, ie, an IEEE 802.11n system, as well as a VHT/HE/EHT (ie, IEEE 802.11ac/ax/be) system. In addition, the technical features of FIG. 18 can be equally applied to the next-generation WIFI standard with various names.

The LTF signal of FIG. 18 includes a plurality of LTF symbols. A plurality of LTF symbols are generated based on the LTF generation sequence. The LTF generation sequence may be expressed as LTF _k (or LTF_k). The LTF generation sequence (LTF _k ) may be multiplied by the LTF mapping matrix P _LTF by the transmitting STA. Since the LTF mapping matrix may include rows that are orthogonal to each other, it may be called an orthogonal matrix, or may simply be called a P matrix or a mapping matrix.

The orthogonal matrix P _LTF may be applied to the LTF generation sequence. “Application” may mean mathematical multiplication. Since the LTF generation sequence to which the P matrix is applied has orthogonality for each stream, it may be used for channel estimation (ie, channel estimation for a MIMO channel) in the receiving STA.

For the LTF generation sequence to which the P matrix is applied, a cyclic shift delay (CSD) process for preventing unintentional beamforming is applied, and an antenna mapping matrix Q _k for k subcarriers is mapped to the transmit antenna. can be Q _k serves to map the space-time stream (STS) and the transmit chain. The LTF generation sequence mapped to each transmission chain may be transmitted through a transmission antenna through an Inverse Fast Fourier Transform (IFFT) or IDFT. In this specification, the IFFT operation may be replaced with the IDFT operation.

19 is a diagram illustrating a concept of constructing an LTF symbol based on a conventional HT-LTF generation sequence.

In an example of FIG. 19 , the horizontal axis represents the time axis, and the vertical axis represents the stream STS. That is, in the example of FIG. 19 , the horizontal axis may indicate the number of HTLTF symbols (eg, the number of OFDM symbols), and the vertical axis may indicate the number of supported streams.

When the P matrix is applied to the LTF generation sequence (ie, the HTLTF generation sequence) preset by the transmitting STA (ie, when the P matrix is multiplied or applied to the LTF generation sequence according to the example of FIG. 18 ), the transmitting STA is shown in FIG. 18 / An LTF symbol as in the example of 19 may be configured.

The P matrix applied to FIG. 19 may be represented by P_HTLTF, and may be expressed by the following Equation.

As in the example of FIG. 19 , an LTF symbol (training symbol) is defined in units of streams (ie, Spatial Stream or Space Time Stream), and may be transmitted for channel estimation of each spatial stream. For example, when the number of spatial streams is 1, 2, and 4, 1, 2, and 4 LTF symbols may be transmitted, respectively, but when the number of spatial streams is 3, one long training signal symbol (long training symbol) symbol) by adding 4 LTFs can be used.

19, when the P matrix is applied to a preset LTF generation sequence, the receiving STA may perform channel estimation through the LTF symbol. That is, when the structure of the P matrix is known in advance between the transmitting and receiving STAs, the receiving STA may perform channel estimation according to various conventional methods. In other words, if the structure of the P matrix is defined, a method of performing channel estimation through an LTF symbol to which the corresponding P matrix is applied can be easily implemented by those skilled in the art.

For example, when the P matrix is determined as shown in Equation 2 below, and the LTF generation sequence to which the P matrix is applied is a conventional HTLTF generation sequence, channel estimation at the receiving STA may be performed according to the following example.

Specifically, the LTF symbol received by the receiving STA may be as shown in Equation (3).

where h _nm is the channel between the nth antenna of the sender and the mth antenna of the receiver, P _n (t) is the training symbol transmitted from the nth antenna of the sender, and n _m (t) is the channel experienced by the mth antenna of the receiver. It stands for AWGN (Additive White Gaussian Noise). If the expression is rearranged by substituting the training symbol in Equation 3, the following Equation 4 can be obtained.

In Equation 4, if h _nm is obtained for all n and m, Equation 5 is obtained.

That is, if the structure of the P matrix is defined, the receiving STA may perform channel estimation based on the LTF symbol to which the corresponding P matrix is applied. Although the above example is an example to which the example of Equation 2 is applied, even when an orthogonal matrix of various sizes is applied instead of the example of Equation 2, it is possible for the receiving STA to obtain h _nm based on the conventional algorithm.

Accordingly, in the following, the structure of the P matrix is clearly defined for convenience of description, but a description of a specific equation for performing channel estimation based on the LTF generation sequence to which the corresponding P matrix is applied will be omitted.

In the conventional IEEE 802.11ac and 11ax systems, a structure of a P matrix supporting up to 8 streams has been proposed. For example, the P matrix of Equation 2 may be used for two streams. In addition, the P matrix of Equation 1 may be used for three or four streams. In addition, when the total number of streams is 5 or 6, the 6-by-6 matrix of Equation 6 below may be used.

w=exp(-j*2pi/6).

For reference, in this specification, pi means π.

Also, when the total number of streams is 7 or 8, the 8-by-8 matrix of Equation 7 may be used.

The above-described 2-by-2 P matrix (eg, the matrix of Equation 2) is [1, 1; 1, -1]. In addition, the above-described 4-by-4 P matrix (eg, the matrix of Equation 1 or the P_4x4 matrix of Equation 6) is [1, 1, 1, 1; 1, -1, 1, -1; 1, 1, -1, -1; 1, -1, -1, 1].

When generating an LTF signal based on any one of the above-described 2-by-2 P matrix, 4-by-4 P matrix, 6-by-6 P matrix, and 8-by-8 P matrix, one LTF The number of LTF symbols included in the signal may be as shown in Table 10. For example, for two streams, two initial LTFs may be generated based on the P matrix of Equation 2 (ie, a 2-by-2 matrix). For example, for three or four streams, four initial LTFs may be generated based on the P matrix of Equation 1 (ie, a 4-by-4 matrix). For example, for 5 or 6 streams, 6 Initial LTFs may be generated based on the P matrix of Equation 6 (ie, a 6-by-6 matrix). For example, for 7 or 8 streams, 8 Initial LTFs may be generated based on the P matrix of Equation 7 (ie, an 8-by-8 matrix).

Total N_ss (Initial) N_LTF One One 2 2 3 4 4 4 5 6 6 6 7 8 8 8

The LTF signal of the present specification may additionally include an Extra LTF symbol as well as the aforementioned Initial LTF symbol. The Initial LTF symbol may be generated based on a multiplication between a) a preset LTF generation sequence and b) a conventional P matrix (eg, P matrix of Equations 1, 2, 6, and 7). As shown in Table 10, the total number of initial LTF symbols is equal to the total number of spatial streams (Total N_ss) configured in the transmitting STA, or is set to be larger than the total number of spatial streams (Total N_ss) by '1'. can The Initial LTF symbol may be called by various names (eg, Initial EHT LTF symbol, first type LTF symbol, etc.).

The Extra LTF symbol may mean an LTF symbol consecutive to the Initial LTF symbol. That is, one LTF signal may be composed of the Initial LTF symbol and the Extra LTF symbol. That is, the total number of LTF symbols included in the LTF signal of the present specification may be equal to the sum of the total number of the Initial LTF symbols and the total number of the Extra LTF symbols. The Extra LTF symbol may be called by various names (eg, Extra EHT LTF symbol, second type LTF symbol, etc.).

In the IEEE 802.11be standard (ie, the 11be standard), a maximum of 16 LTF symbols may be supported. That is, the 11be standard may use an increased number of LTF symbols, and accordingly, the 11be standard may include an LTF signal (ie, an EHT LTF signal) composed of an Initial LTF symbol and an Extra LTF symbol proposed in this specification. .

More specifically, in the 11be standard/system, a maximum of 16 spatial streams may be supported, and an STA may receive up to 16 LTF symbols. In addition, information on whether the STA supports up to 16 spatial streams and/or up to 16 LTF symbols may be included in PHY capability (information). For example, the PHY capability (information) may be included in the EHT PHY Capabilities Information. The EHT PHY Capabilities Information may be included in the EHT Capabilities element.

20 is a block diagram illustrating the format of an EHT Capabilities element. The EHT Capabilities element of FIG. 20 may be included in the Management frame. Examples of the management frame may be a Beacon frame, a Probe Response frame, a (Re)Association Request frame, and a (Re)Association Response frame.

The EHT PHY Capabilities Information may include a total of 64 bits of information consisting of B0 bits to B63 bits. For example, information on whether the STA supports up to 16 spatial streams and/or up to 16 LTF symbols may be indicated by 5-bit information in EHT PHY Capabilities Information, and the 5-bit information is B46 bits to It may consist of B50 bits.

Meanwhile, when a signal is transmitted through MU-MIMO communication, the maximum number of supportable spatial streams (N_SS) per STA may be “4”. Accordingly, the maximum number of streams for MU-MIMO may be set to 16, and accordingly, a maximum of 16 LTF symbols may be used through MU-MIMO communication.

The STA of the present specification may transmit and receive signals using a plurality of SSs. In this case, in order to improve the reception performance (eg, channel estimation performance) of the reception STA, the transmission STA may use an increased number of LTF symbols. That is, the transmitting STA preferably includes an Extra LTF symbol as well as an Initial LTF symbol in one LTF signal. The number of Extra LTF symbols may not exceed the number of Initial LTF symbols. This is because, when the number of Extra LTF symbols is excessively increased, the time required for the LTF signal becomes excessively long and overhead may occur.

Table 11 shows the total number of spatial streams (Total N_ss) and the number of Initial/Extra LTF symbols configured by the transmitting STA. For example, when the total number of spatial streams (Total N_ss) is determined to be 3, the number of Initial LTF symbols (Initial N_LTF) is fixed to 4 as shown in Table 10, and the number of Extra LTF symbols (Extra N_LTF) may be determined as 1, 2, 3, or 4. Accordingly, the total number of LTF symbols included in one LTF signal (Total N_LTF) may be determined to be 5, 6, 7, or 8.

Total N_ss Initial N_LTF Extra N_LTF Total N_LTF One One One 2 2 2 1/2 3/4 3 4 1/2/3/4 5/6/7/8 4 4 1/2/3/4 5/6/7/8 5 6 1/2/3/4/5/6 7/8/9/10/11/12 6 6 1/2/3/4/5/6 7/8/9/10/11/12 7 8 1/2/3/4/5/6/7/8 9/10/11/12/13/14/15/16 8 8 1/2/3/4/5/6/7/8 9/10/11/12/13/14/15/16

As shown in Table 11, the maximum value of the total number of LTF symbols (Total N_LTF) included in the LTF signal of the present specification may be 2, 4, 8, 12, or 16 according to the number of streams.

In addition, the Extra LTF symbol of the present specification may be used for MU-MIMO transmission. In this case, the maximum number of spatial streams (Max N_ss) that can be supported by the STA may be “4”. Accordingly, when MU-MIMO transmission is performed, only the case where extra N_LTF is 1, 2, 3, or 4 in Table 11 may be considered. Therefore, when the extra LTF for MU-MIMO transmission is used, the maximum value of the total number of LTF symbols (Total N_LTF) according to each N_SS may be 2, 4, or 8.

The number of Extra LTF symbols in the present specification may be variously set as shown in Table 11. When the Extra LTF symbol is included, the total number of LTF symbols included in one LTF signal increases. That is, in response to a specific number of streams, a larger number of LTF symbols than in Table 10 are included in one LTF signal.

Hereinafter, an example of a plurality of LTF symbols through a P matrix configured based on the total number of LTF symbols included in one LTF signal (= the number of Initial LTF symbols + the number of Extra LTF symbols) will be described. The total number of LTF symbols included in one LTF signal may be expressed as “TN_LTF”, and the number of Initial LTF symbols included in one LTF signal may be expressed as “IN_LTF”, and the number of LTF symbols included in one LTF signal may be expressed as “IN_LTF”. The number of Extra LTF symbols may be indicated as “EN_LTF”. For example, the IN_LTF may be determined as shown in Table 10 according to the number of corresponding spatial streams (N_SS).

19 and Equation 1, the number of rows of the P matrix for the LTF signal may correspond to the number of spatial streams related to the P matrix, and the number of columns of the P matrix The number may correspond to the number of LTF symbols generated through the P matrix. For example, an EHT LTF symbol may be generated by multiplying a preset EHT LTF sequence by at least a part of the P matrix (ie, all or part of the P matrix). For example, the number of rows of the P matrix multiplied by the EHT LTF sequence may be equal to the number of spatial streams related to the P matrix. For example, the number of columns of the P matrix multiplied by the EHT LTF sequence may be the same as the number of generated EHT LTF symbols.

Hereinafter, a technical feature of generating an Extra LTF symbol in addition to the Initial LTF symbol will be described. That is, the technical characteristics of the P matrix used to construct a plurality of consecutive LTF symbols for one LTF signal will be described below.

Technical Features 1.

Hereinafter, an example of configuring the P matrix based on TN_LTF is proposed. For example, the number of columns of the P matrix used in the following example may be set based on TN_LTF. For example, the number of columns of the P matrix may be equal to TN_LTF.

Technical Features 1.a.

21 is a diagram illustrating an example in which a P matrix corresponding to TN_LTF is used.

Since TN_LTF is IN_LTF + EN_LTF, a P matrix corresponding to the TN_LTF may be used. In other words, in the example of FIG. 21 , one P matrix (P Matrix_A) is used, and the number of columns of the matrix of FIG. 21 may be the same as TN_LTF. In other words, the number of columns of the P matrix multiplied by the LTF sequence may be equal to TN_LTF.

For example, since the P matrix (P Matrix_A) of FIG. 21 is determined based on the number of generated LTF symbols (ie, TN_LTF), the P matrix (P Matrix_A) of FIG. 21 is the number of spatial streams (N_ss) or It may be determined regardless of IN_LTF. That is, the number of rows of the conventional P matrix is related to the number of spatial streams (N_ss), but the number of rows of the P matrix (P Matrix_A) of FIG. 21 is independent of the number of spatial streams (N_ss) can do. In addition, the number of columns of the conventional P matrix is related to IN_LTF, but the number of columns of the P matrix (P Matrix_A) of FIG. 21 is not IN_LTF, but TN_LTF (=IN_LTF + EN_LTF). .

In some of the following examples, the maximum value of TN_LTF is assumed to be 8, but the technical features of the present specification are not limited thereto. That is, it is possible to apply the following technical characteristics to various values (TN_LTF).

Technical Features 1.a.i.

For example, TN_LTF may be set to “2”. In this case, a preset LTF sequence (eg, VHT/HE/EHT LTF sequence) may be multiplied by a 2-by-2 P matrix (or a 2-by-2 part in a 4-by-4 P matrix). . For example, the 2-by-2 P matrix may be the matrix of Equation 2, and the 4-by-4 P matrix may be the matrix of Equation 1 above.

Technical Features 1.a.ii.

For example, TN_LTF may be set to “4”. In this case, a 4-by-4 P matrix may be multiplied by a preset LTF sequence (eg, VHT/HE/EHT LTF sequence). For example, the 4-by-4 P matrix may be the matrix of Equation 1 above.

When TN_LTF is set to “4”, for example, IN_LTF=2 and EN_LTF=2 may be set. That is, the matrix P Matrix_A of FIG. 21 is composed of a 4-by-4 P matrix, and two Initial LTF symbols and two Extra LTF symbols may be generated based on the 4-by-4 P matrix. In this case, the number of related spatial streams (N_ss) may be determined to be 2. In this case, the P matrix multiplied by the preset LTF sequence may be a 2-by-4 matrix/component among 4-by-4 P matrices. These technical characteristics can be applied as it is even when TN_LTF is changed.

For example, TN_LTF may be set to “3”. Even in this case, as described above, the matrix P Matrix_A of FIG. 21 may be configured as a 4-by-4 P matrix. For example, when TN_LTF is set to “3”, the number of related spatial streams (N_ss) may be 2, IN_LTF=2, EN_LTF=1. In this case, the P matrix multiplied by the preset LTF sequence may be a 2-by-3 matrix/component among 4-by-4 P matrices. These technical characteristics can be applied as it is even when TN_LTF is changed.

Technical Features 1.a.iii.

For example, TN_LTF may be set to “8”. In this case, an 8-by-8 P matrix may be multiplied by a preset LTF sequence (eg, VHT/HE/EHT LTF sequence). For example, the 8-by-8 P matrix may be the matrix of Equation 7 above.

When TN_LTF is set to “8”, for example, IN_LTF=4 and EN_LTF=4 may be set. That is, the matrix P Matrix_A of FIG. 21 is composed of an 8-by-8 P matrix, and 4 Initial LTF symbols and 4 Extra LTF symbols may be generated based on the 8-by-8 P matrix. In this case, the number of related spatial streams (N_ss) may be determined to be 4. In this case, the P matrix multiplied by the preset LTF sequence may be a 4-by-8 matrix/component among 8-by-8 P matrices. These technical characteristics can be applied as it is even when TN_LTF is changed to “5”, 6”, “7”, etc.

For example, TN_LTF may be set to “7”. Even in this case, as described above, the matrix P Matrix_A of FIG. 21 may be configured as an 8-by-8 P matrix. For example, when TN_LTF is set to “7”, the number of related spatial streams (N_ss) may be 4, IN_LTF=4, EN_LTF=3. In this case, at least a part of the P matrix multiplied by the preset LTF sequence may be a 4-by-7 matrix/component among the 8-by-8 P matrix.

For example, TN_LTF may be set to “5” or “6”. Even in this case, as described above, the matrix P Matrix_A of FIG. 21 may be configured as an 8-by-8 P matrix.

Technical Features 1.a.iv.

For example, when TN_LTF is set to “6” or “5”, the preset LTF sequence (eg, VHT/HE/EHT LTF sequence) is not an 8-by-8 P matrix but a 6-by-6 The P matrix can be multiplied. The 6-by-6 P matrix may be the matrix of Equation (6).

Technical features 2.

Hereinafter, an example of configuring the P matrix based on the total number of spatial streams (Total N_SS) and/or IN_LTF is proposed. For example, the number of rows of the P matrix used in the following example may be set based on the total number of spatial streams (Total N_SS) and/or IN_LTF. For example, the number of rows of the P matrix may be equal to the total number of spatial streams (Total N_SS) and/or IN_LTF.

Technical Features 2.a.

22 is a diagram illustrating an example in which a P matrix corresponding to the total number of spatial streams or IN_LTF is used. The matrix P Matrix_B of FIG. 22 may be composed of two P matrices as shown, and may be composed of the same two P matrices or two different P matrices.

For example, the P matrix of FIG. 22 may be determined by the allocated N_SS or Total N_SS. In addition, the IN_LTF may be determined based on the allocated N_SS or Total N_SS, for example, based on Table 11 above. Accordingly, as a result, the P matrix of FIG. 22 may be constructed based on the total number of spatial streams (Total N_SS) and/or IN_LTF. In other words, the number of rows of the P matrix P Matrix_B of FIG. 22 may be determined based on Total N_SS. For example, the number of rows of the P matrix P Matrix_B of FIG. 22 may be determined based on IN_LTF. For example, the number of rows of the P matrix P Matrix_B of FIG. 22 may be equal to Total N_SS.

For example, an Initial LTF symbol may be generated through the left P matrix of FIG. 22 , and an Extra LTF symbol may be generated through the right P matrix of FIG. 22 . For example, the number of columns of the left P matrix of FIG. 22 multiplied by a preset LTF sequence (eg, VHT/HE/EHT LTF sequence) may be the same as the number of Initial LTF symbols. For example, the number of columns of the right P matrix of FIG. 22 multiplied by the preset LTF sequence may be the same as the number of Extra LTF symbols.

Technical Features 2.b.

The following example is described based on TN_LTF. Hereinafter, the case where TN_LTF is set to 2, 4, and 8 will be mainly described, but the value of TN_LTF is set in various ways, and even in this case, the technical features of the present specification may be applied. An example of configuring the P matrix of FIG. 22 for various TN_LTFs will be described as follows.

Technical Features 2.b.i.

For example, TN_LTF may be set to “2”. In this case, a 1-by-1 matrix/component is multiplied by a preset LTF sequence (eg, a VHT/HE/EHT LTF sequence) from a 2-by-2 P matrix (or a 4-by-4 P matrix). In this way, an Initial LTF symbol may be generated, and an Extra LTF symbol may be generated in the same way. For example, the 2-by-2 P matrix may be the matrix of Equation 2, and the 4-by-4 P matrix may be the matrix of Equation 1 above.

Technical Features 2.b.ii.

For example, TN_LTF may be set to “4”. In this case, the preset LTF sequence (eg, VHT/HE/EHT LTF sequence) is multiplied by the 2-by-2 P matrix (or the 2-by-2 matrix/component among the 4-by-4 P matrix). can For example, the 2-by-2 P matrix may be the matrix of Equation 2, and the 4-by-4 P matrix may be the matrix of Equation 1 above.

When TN_LTF is set to “4”, for example, IN_LTF=2 and EN_LTF=2 may be set. That is, the left P matrix of FIG. 22 is composed of a 2-by-2 P matrix (or a 2-by-2 matrix/component of a 4-by-4 P matrix), and the corresponding 2-by-2 P matrix (or 4-by-4 P matrix). Two Initial LTF symbols may be generated based on a 2-by-2 matrix/component) among the by-4 P matrix. In addition, the right P matrix of FIG. 22 is composed of the same matrix as the left P matrix, and two Extra LTF symbols may be generated based on the matrix.

For example, TN_LTF may be set to “3”. Even in this case, as described above, the matrix P Matrix_B of FIG. 22 may be configured as a 2-by-2 P matrix. For example, when TN_LTF is set to “3”, the number of related spatial streams (N_ss) may be 2, IN_LTF=2, EN_LTF=1. In this case, the entire 2-by-2 P matrix may be used in the left matrix of FIG. 22 used for the Initial LTF symbol (that is, the preset LTF sequence may be multiplied by all the 2-by-2 P matrices) have). In other words, the left matrix of FIG. 22 is configured based on the number of spatial streams (N_ss=2), and accordingly, the 2-by-2 P matrix may be configured as the left matrix of FIG. 22 . Meanwhile, a part of the 2-by-2 P matrix may be used for the right matrix of FIG. 22 used for the Extra LTF symbol. That is, as the P matrix for the Extra LTF symbol, a 1-by-1 matrix/component of the 2-by-2 P matrix may be used (that is, 1-by- of the 2-by-2 P matrix in the preset LTF sequence). 1 matrix/component can be multiplied).

Technical Features 2.b.iii.

For example, TN_LTF may be set to “8”. In this case, an 8-by-8 P matrix may be multiplied by a preset LTF sequence (eg, VHT/HE/EHT LTF sequence). For example, the 8-by-8 P matrix may be the matrix of Equation 7 above.

When TN_LTF is set to “8”, for example, IN_LTF=4 and EN_LTF=4 may be set. That is, both the left matrix and the right matrix of FIG. 22 are composed of a 4-by-4 P matrix, four Initial LTF symbols are generated based on the left 4-by-4 P matrix, and the right 4-by-4 P matrix is formed. Four Extra LTF symbols may be generated on the basis. In this case, the number of related spatial streams (N_ss) may be determined to be 4. These technical characteristics can be applied as it is even when TN_LTF is changed to “5”, 6”, “7”, etc.

For example, TN_LTF may be set to “7”. In this case, as described above, both the left matrix of FIG. 22 and the right matrix of FIG. 22 may be configured as a 4-by-4 P matrix. For example, when TN_LTF is set to “7”, the number of related spatial streams (N_ss) may be 4, IN_LTF=4, EN_LTF=3. In this case, the P matrix for the Initial LTF symbol (ie, the left matrix of FIG. 22 ) may be configured as a 4-by-4 matrix based on N_ss and/or IN_LTF. In addition, the P matrix for the Extra LTF symbol (ie, the right matrix of FIG. 22 ) may be at least a part of the P matrix (ie, the left matrix of FIG. 22 ) for the Initial LTF symbol. That is, as for the P matrix for the Extra LTF symbol (ie, the matrix on the right side of FIG. 22), a 4-by-3 matrix/component among the 4-by-4 P matrix may be used (ie, 4-by-3 matrix/component in the preset LTF sequence). It can be multiplied by a 4-by-3 matrix/component of a by-4 P matrix).

The above-described specific values of TN_LTF, IN_LTF, and EN_LTF may be variously modified. For example, TN_LTF may be set to “6”. In this case, the number of related spatial streams (N_ss) may be 4, and IN_LTF=4, EN_LTF=2. In this case, based on the above-described technical features, the P matrix for the Initial LTF symbol (ie, the left matrix of FIG. 22) is composed of a 4-by-4 P matrix, and the P matrix for the Extra LTF symbol (ie, the P matrix in FIG. 22) 22), a 4-by-2 matrix/component among the 4-by-4 P matrix may be used for LTF generation.

As described above, the PPDU of the present specification may include a plurality of Initial LTF symbols in one LTF signal and a plurality of Extra LTF symbols consecutive to the plurality of Initial LTF symbols. In this case, the transmitting STA may transmit information on the Extra LTF symbol to the receiving STA.

For example, the information on the Extra LTF symbol includes first information on whether the Extra LTF symbol is included in the transmission signal/PPDU, and/or the total number of the Extra LTF symbols (or the Initial LTF symbol and the Extra (total sum of LTF symbols) may include second information.

For example, the first information may consist of 1-bit information/subfield. The first information may be included in, for example, the first control signal field (eg, U-SIG field). For example, the first information may be located in some of the various fields shown in Table 8/9, for example, a bit set as a validate bit or a disregard bit. For example, the first information may include any one of B20 to B24 bits of the first U-SIG signal (ie, U-SIG 1 symbol) shown in Table 8 and/or the first information shown in Table 8. 1 U-SIG signal (ie, U-SIG 1 symbol) may be configured through B25 bits or the like. Additionally or alternatively, the first information may be included in the second control signal field (eg, EHT-SIG field). For example, the first information may be configured through any one of bits B13 to B16 bits, which are disregard bits included in the common field of the second control signal field (eg, EHT-SIG field). . For example, the first information may be configured through B15 included in a user field of a user specific field of the second control signal field (eg, EHT-SIG field).

For example, the second information may be composed of N-bit information/subfield (eg, 3 or 4-bit field). For example, the second information may be included in the first control signal field (eg, U-SIG field) or the second second control signal field (eg, EHT-SIG field). For example, the second information may be included in the Number Of EHT-LTF Symbols field located in bits B6 to B8 of the common field of the second control signal field (eg, EHT-SIG field). For example, the second information may be included in 3 bits (or 4 bits) among bits B16 to B19 of the user field of the second control signal field (eg, EHT-SIG field).

The various technical features described above may be applied to a transmitting STA and a receiving STA of a WLAN system.

23 is a flowchart illustrating an operation performed by a transmitting STA. For example, the operation of FIG. 23 may be performed by an AP STA or a non-AP STA. That is, the operation of FIG. 23 may be applied to downlink or uplink.

According to step S2310, the transmitting STA may configure a Long Training Field (LTF) signal for channel estimation. An example of the LTF signal may be the EHT-LTF shown in FIG. 16 . That is, the LTF signal may be located between the STF signal and the data signal (ie, the data field including the PSDU). The LTF signal may include a plurality of consecutive LTF symbols. The plurality of consecutive LTF symbols may include an initial LTF symbol and an extra LTF symbol. In other words, the LTF signal may be transmitted through an initial LTF symbol and an extra LTF symbol.

The number of initial LTF symbols may be determined based on the number of spatial streams configured by the transmitting STA. In other words, the number of initial LTF symbols may be determined based on the total number of spatial streams (Total N_ss) based on Table 10. In other words, the number of the initial LTF symbols is the same as the number of spatial streams or as large as "1" compared to the number of spatial streams, as shown in Table 10 above. .

The number of the extra LTF symbols may be variously set based on the number of the initial LTF symbols. For example, the number of extra LTF symbols may be determined as shown in Table 11 above. For example, the number of extra LTF symbols may be the same as the number of initial LTF symbols. For example, the number of extra LTF symbols may be different from the number of initial LTF symbols.

A method for generating the initial LTF and extra LTF symbols may be determined in various ways. For example, the initial LTF and extra LTF symbols may be generated based on the technical feature of FIG. 21 or the technical feature of FIG. 22 .

For example, when generating the initial LTF symbol and the extra LTF symbol through the example of FIG. 22, the initial LTF symbol is an LTF sequence (eg, a preset HT/VHT/HE/EHT LTF sequence) and It may be configured based on multiplication of at least a portion of the P matrix (eg, the P matrix of Equations 1, 2, 6, and 7). In other words, the P matrix applied to the LTF sequence may be all of the P matrix or a part of the P matrix (ie, a specific row/column). For example, at least a part of the P matrix may be all or a part of the left matrix P Matrix_B of FIG. 22 .

In addition, when the example of FIG. 22 is applied, the extra LTF symbol is the LTF sequence (eg, a preset HT/VHT/HE/EHT LTF sequence) and the P matrix, for example, mathematical It may be constructed based on the product of at least a part of the P matrix of Equations 1, 2, 6, and 7). For example, the P matrix for the extra LTF symbol may be the same as the P matrix for the initial LTF symbol. For example, the P matrix for the extra LTF symbol may be the right matrix (P Matrix_B) of FIG. 22 . The P matrix applied for the extra LTF symbol may be all or a part of the right matrix P Matrix_B of FIG. 22 .

According to step S2310, a transmission physical protocol data unit (PPDU) including the long training field (LTF) signal may be transmitted to at least one receiving STA. For example, the transmission PPDU may be the EHT PPDU shown in FIG. 16 or a PPDU defined according to the next-generation WLAN standard newly defined after the IEEE 802.11be standard. For example, the transmission PPDU is a legacy signal (L-SIG) field, a first control signal field including control information for interpretation of the transmission PPDU, and the first control signal field is continuous and a second control signal field. Specifically, the first control signal field may be the U-SIG field, and the second control signal field may be an EHT-SIG field. The second control signal field may include a common field and a user specific field.

The first control signal field or the second control signal field may include a subfield related to the extra LTF symbol. For example, the subfield regarding the extra LTF symbol may include first control information regarding whether the extra LTF symbol is included in the LTF signal, and/or the extra included in the LTF signal. (extra) may include second control information regarding the number of LTF symbols.

24 is a flowchart illustrating an operation performed by a receiving STA. For example, the operation of FIG. 24 may be performed by an AP STA or a non-AP STA. That is, the operation of FIG. 24 may be applied to downlink or uplink.

According to step S2410, the receiving STA may receive the receiving PPDU including the LTF signal from the transmitting STA. The technical features applied to the received PPDU may be the same as those of the transmit PPDU of FIG. 23 . That is, the LTF signal may be received through an initial LTF symbol and an extra LTF symbol. In addition, the number of initial LTF symbols may be determined based on the number of spatial streams for the received PPDU. In addition, the number of the extra (extra) LTF symbols may be variously set, for example, may be determined based on the private interest table 11. The technical features applied to the received PPDU may be the same as those applied in step S2310.

According to step S2420, the receiving STA may decode the received PPDU. For example, the receiving STA may use a data field (eg, included in the data field) of the received PPDU based on the legacy signal field, the first control signal field, and/or the second control signal field included in the received PPDU. Resource Unit) can be decoded. In order to decode the data field, channel estimation may be performed based on the LTF signal of the received PPDU. The channel estimation may be performed based on the initial LTF symbol and the extra LTF symbol.

Each operation shown in FIGS. 23 to 24 may be performed by the apparatus of FIGS. 1 and/or 14 . For example, the transmitting STA of FIG. 23 or the receiving STA of FIG. 24 may be implemented with the apparatus of FIGS. 1 and/or 14 . The processor of FIGS. 1 and/or 14 may perform each of the operations of FIGS. 23 to 24 described above. In addition, the transceiver of FIGS. 1 and/or 14 may perform each operation described in FIGS. 23 to 24 .

The apparatus proposed in this specification (eg, a transmitting STA and a receiving STA) does not necessarily include a transceiver, and may be implemented in the form of a chip including a processor and a memory. Such a device may generate/store the transmit/receive PPDU according to the above-described example. Such a device may be connected to a separately manufactured transceiver to support actual transmission and reception.

The present specification proposes a computer-readable recording medium implemented in various forms. A computer readable medium according to the present specification may be encoded with at least one computer program including instructions. The instructions stored in the medium may control the processor described in FIGS. 1 and/or 14 . That is, the instructions stored in the medium control the processor presented herein to perform the above-described operations of the transmitting and receiving STAs (eg, FIGS. 23 to 24 ).

The technical features of the present specification described above are applicable to various applications or business models. For example, the above-described technical features may be applied for wireless communication in a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field that studies artificial intelligence or methodologies that can make it, and machine learning refers to a field that defines various problems dealt with in the field of artificial intelligence and studies methodologies to solve them. do. Machine learning is also defined as an algorithm that improves the performance of a certain task through continuous experience.

An artificial neural network (ANN) is a model used in machine learning, and may refer to an overall model having problem-solving ability, which is composed of artificial neurons (nodes) that form a network by combining synapses. An artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process that updates model parameters, and an activation function that generates an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include neurons and synapses connecting neurons. In the artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through synapses.

Model parameters refer to parameters determined through learning, and include the weight of synaptic connections and the bias of neurons. In addition, the hyperparameter refers to a parameter to be set before learning in a machine learning algorithm, and includes a learning rate, the number of iterations, a mini-batch size, an initialization function, and the like.

The purpose of learning the artificial neural network can be seen as determining the model parameters that minimize the loss function. The loss function may be used as an index for determining optimal model parameters in the learning process of the artificial neural network.

Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning according to a learning method.

Supervised learning refers to a method of training an artificial neural network in a state in which a label for the training data is given, and the label is the correct answer (or result value) that the artificial neural network must infer when the training data is input to the artificial neural network. can mean Unsupervised learning may refer to a method of training an artificial neural network in a state where no labels are given for training data. Reinforcement learning can refer to a learning method in which an agent defined in an environment learns to select an action or sequence of actions that maximizes the cumulative reward in each state.

Among artificial neural networks, machine learning implemented as a deep neural network (DNN) including a plurality of hidden layers is also called deep learning (deep learning), and deep learning is a part of machine learning. Hereinafter, machine learning is used in a sense including deep learning.

In addition, the above-described technical features can be applied to the wireless communication of the robot.

A robot can mean a machine that automatically handles or operates a task given by its own capabilities. In particular, a robot having a function of recognizing an environment and performing an operation by self-judgment may be referred to as an intelligent robot.

Robots can be classified into industrial, medical, home, military, etc. depending on the purpose or field of use. The robot may be provided with a driving unit including an actuator or a motor to perform various physical operations such as moving the robot joints. In addition, the movable robot includes a wheel, a brake, a propeller, and the like in the driving unit, and can travel on the ground or fly in the air through the driving unit.

In addition, the above-described technical features may be applied to devices supporting extended reality.

The extended reality is a generic term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology provides only CG images of objects or backgrounds in the real world, AR technology provides virtual CG images on top of images of real objects, and MR technology is a computer that mixes and combines virtual objects in the real world. graphic technology.

MR technology is similar to AR technology in that it shows both real and virtual objects. However, there is a difference in that in AR technology, virtual objects are used in a form that complements real objects, whereas in MR technology, virtual objects and real objects are used with equal characteristics.

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phone, tablet PC, laptop, desktop, TV, digital signage, etc. can be called

Claims (15)

In the method used in a wireless LAN (Wireless Local Area Network) system, In the transmitting STA (station), configuring a LTF (Long Training Field) signal for channel estimation, The number of LTF symbols included in the LTF signal is the sum of the number of initial LTF symbols and the number of extra LTF symbols, The number of initial LTF symbols is determined based on the number of spatial streams configured by the transmitting STA, The initial LTF symbol is configured based on the multiplication of at least a part of the LTF sequence and the P matrix, The P matrix is determined based on the number of spatial streams, The number of extra LTF symbols is determined based on the number of initial LTF symbols, wherein the extra LTF symbol is configured based on a multiplication of at least a portion of the LTF sequence and the P matrix; and Transmitting, by the transmitting STA, a transmission Physical Protocol Data Unit (PPDU) including the LTF signal to at least one receiving STA How to include. The method of claim 1, For two spatial streams, the P matrix is determined as a 2-by-2 matrix, the number of the initial LTF symbols is determined as two, and the number of the extra LTF symbols is determined as two, and , the number of LTF symbols included in the LTF signal is 4, For the two spatial streams, the initial LTF symbol is constructed based on the product of all of the LTF sequence and the P matrix, and the extra LTF symbol is based on the product of the LTF sequence and all of the P matrix. how it is composed. According to claim 1, For two spatial streams, the P matrix is determined as a 2-by-2 matrix, the number of initial LTF symbols is determined as two, and the number of the extra LTF symbols is determined as one, and , the number of LTF symbols included in the LTF signal is three, For the two spatial streams, the initial LTF symbol is constructed based on the product of both the LTF sequence and the P matrix, and the extra LTF symbol is 1 contained in the LTF sequence and the P matrix. How it is constructed based on the product of -by-1 matrices. According to claim 1, For 4 spatial streams, the P matrix is determined as a 4-by-4 matrix, the number of the initial LTF symbols is determined as 4, and the number of the extra LTF symbols is determined as 4, and , the number of LTF symbols included in the LTF signal is 8, For the four spatial streams, the initial LTF symbol is constructed based on the product of all of the LTF sequence and the P matrix, and the extra LTF symbol is based on the product of the LTF sequence and all of the P matrix. how it is composed. The method of claim 1, For 4 spatial streams, the P matrix is determined as a 4-by-4 matrix, the number of the initial LTF symbols is determined as 4, and the number of the extra LTF symbols is determined as 2, and , the number of LTF symbols included in the LTF signal is 6, For the four spatial streams, the initial LTF symbol is constructed based on the product of all of the LTF sequence and the P matrix, and the extra LTF symbol is included in the LTF sequence and the P matrix. How it is constructed based on the product of -by-2 matrices. According to claim 1, The transmission PPDU is an extremely high throughput (EHT) PPDU. Way. The method of claim 1, Transmitting a management frame including a capability bit regarding whether the transmitting STA supports the extra LTF symbol to the receiving STA further comprising Way. The method of claim 1, The number of initial LTF symbols is configured as shown in Table 12 below based on the number of spatial streams. number of spatial streams Number of initial LTF symbols One One 2 2 3 4 4 4 5 6 6 6 7 8 8 8 According to claim 1, The transmission PPDU includes a first control signal field and a second control signal field consecutive to the first control signal field, The first control signal field or the second control signal field includes a subfield related to the extra LTF symbol Way. 10. The method of claim 9, The subfield regarding the extra LTF symbol includes first control information regarding whether the extra LTF symbol is included in the LTF signal, and/or the extra LTF included in the LTF signal. including second control information on the number of symbols Way. In a transmitting STA (station) of a wireless local area network (WLAN) system, a transceiver for transmitting and receiving radio signals; and a processor that controls the transceiver including, The processor is Configure a Long Training Field (LTF) signal for channel estimation, wherein the number of LTF symbols included in the LTF signal is the sum of the number of initial LTF symbols and the number of extra LTF symbols, and the initial ( initial) the number of LTF symbols is determined based on the number of spatial streams configured by the transmitting STA, and the initial LTF symbol is a multiplication of at least a portion of an LTF sequence and a P matrix ), the P matrix is determined based on the number of spatial streams, the number of extra LTF symbols is determined based on the number of the initial LTF symbols, and the extra (extra) an LTF symbol is constructed based on a multiplication of at least a portion of the LTF sequence and the P matrix; configured to transmit a transmission PPDU (Physical Protocol Data Unit) including the LTF signal to at least one receiving STA through the transceiver Device. In the method used in a wireless LAN (Wireless Local Area Network) system, At the receiving STA (station), receiving a receiving PPDU (Physical Protocol Data Unit) from the transmitting STA, The genital reception PPDU includes a Long Training Field (LTF) signal for channel estimation, The number of LTF symbols included in the LTF signal is the sum of the number of initial LTF symbols and the number of extra LTF symbols, The number of initial LTF symbols is determined based on the number of spatial streams configured by the transmitting STA, The initial LTF symbol is configured based on the multiplication of at least a part of the LTF sequence and the P matrix, The P matrix is determined based on the number of spatial streams, The number of extra LTF symbols is determined based on the number of initial LTF symbols, wherein the extra LTF symbol is configured based on a multiplication of at least a portion of the LTF sequence and the P matrix; and Decoding the received PPDU, at the receiving STA containing Way. In a receiving STA (station) of a wireless local area network (WLAN) system, a transceiver for transmitting and receiving radio signals; and a processor that controls the transceiver including, The processor is A reception Physical Protocol Data Unit (PPDU) is received from the transmitting STA through the transceiver, but the reception PPDU includes a Long Training Field (LTF) signal for channel estimation, and the number of LTF symbols included in the LTF signal is It is the sum of the number of initial LTF symbols and the number of extra LTF symbols, and the number of initial LTF symbols is based on the number of spatial streams configured by the transmitting STA. is determined, the initial LTF symbol is constructed based on a multiplication of at least a part of an LTF sequence and a P matrix, the P matrix is determined based on the number of spatial streams, and the extra ) The number of LTF symbols is determined based on the number of initial LTF symbols, and the extra LTF symbols are based on the multiplication of at least a portion of the LTF sequence and the P matrix. become; configured to decode the received PPDU Device. At least one computer-readable recording medium including an instruction based on being executed by at least one processor included in a STA (station) of a wireless local area network system in a readable medium), Configure a Long Training Field (LTF) signal for channel estimation, wherein the number of LTF symbols included in the LTF signal is the sum of the number of initial LTF symbols and the number of extra LTF symbols, and the initial ( initial) the number of LTF symbols is determined based on the number of spatial streams configured by the transmitting STA, and the initial LTF symbol is a multiplication of at least a portion of an LTF sequence and a P matrix ), the P matrix is determined based on the number of spatial streams, the number of extra LTF symbols is determined based on the number of the initial LTF symbols, and the extra (extra) the LTF symbol is constructed based on a multiplication of at least a portion of the LTF sequence and the P matrix; and Transmitting a transmission PPDU (Physical Protocol Data Unit) including the LTF signal to at least one receiving STA to perform an operation including Device. In the apparatus (apparatus) of a wireless local area network (Wireless Local Area Network) system, Memory; and a processor that controls the memory including, The processor is Configure a Long Training Field (LTF) signal for channel estimation, wherein the number of LTF symbols included in the LTF signal is the sum of the number of initial LTF symbols and the number of extra LTF symbols, and the initial ( initial) the number of LTF symbols is determined based on the number of spatial streams configured by the transmitting STA, and the initial LTF symbol is a multiplication of at least a portion of an LTF sequence and a P matrix ), the P matrix is determined based on the number of spatial streams, the number of extra LTF symbols is determined based on the number of the initial LTF symbols, and the extra (extra) an LTF symbol is constructed based on a multiplication of at least a portion of the LTF sequence and the P matrix; configured to transmit a transmission PPDU (Physical Protocol Data Unit) including the LTF signal to at least one receiving STA Device.

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